Builds upon the existing NVIDIA 16Bx2 block linear
format modifiers by adding more "fields" to the
existing parameterized
DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK format modifier
macro that allow fully defining a unique-across-
all-NVIDIA-hardware bit layout using a minimal
set of fields and values. The new modifier macro
DRM_FORMAT_MOD_NVIDIA_BLOCK_LINEAR_2D is
effectively backwards compatible with the existing
macro, introducing a superset of the previously
definable format modifiers.
Backwards compatibility has two quirks. First,
the zero value for the "kind" field, which is
implied by the DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK
macro, must be special cased in drivers and
assumed to map to the pre-Turing generic kind of
0xfe, since a kind of "zero" is reserved for
linear buffer layouts on all GPUs.
Second, it is assumed backwards compatibility
is only needed when running on Tegra GPUs, and
specifically Tegra GPUs prior to Xavier. This
is based on two assertions:
-Tegra GPUs prior to Xavier used a slightly
different raw bit layout than desktop GPUs,
making it impossible to directly share block
linear buffers between the two.
-Support for the existing block linear modifiers
was incomplete, making them useful only for
exporting buffers created by nouveau and
importing them to Tegra DRM as framebuffers for
scan out. There was no support for adding
framebuffers using format modifiers in nouveau,
nor importing dma-buf/PRIME GEM objects into
nouveau userspace drivers with modifiers in Mesa.
Hence it is assumed the prior modifiers were not
intended for use on desktop GPUs, and as a
corollary, were not intended to support sharing
block linear buffers across two different NVIDIA
GPUs.
v2:
- Added canonicalize helper function
v3:
- Added additional bit to compression field to
support Tesla (NV5x,G8x,G9x,GT1xx,GT2xx) class
chips.
Signed-off-by: James Jones <jajones@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
UAPI Changes:
- drm/i915: Show per-engine default property values in sysfs
By providing the default values configured into the kernel via sysfs, it
is much more convenient for userspace to restore those sane defaults, or
at least know what are considered good baseline. This is useful, for
example, to cleanup after any failed userspace prior to commencing new
jobs.
Cross-subsystem Changes:
- video/hdmi: Add Unpack only function for DRM infoframe
- Includes pull request gvt-next-2020-05-12
Driver Changes:
- Restore Cherryview back to full-ppgtt (Chris, Mika)
- Document locking guidelines for i915 (Chris, Daniel, Joonas)
- Fix GitLab #1746: Handle idling during i915_gem_evict_something busy loops (Chris)
- Display WA #1105: Require linear fb stride to be multiple of 512 bytes on
gen9/glk (Ville)
- Add Wa_14010685332 for ICP/ICL (Matt R)
- Restrict w/a 1607087056 for EHL/JSL (Swathi)
- Fix interrupt handling for DP AUX transactions on Tigerlake (Imre)
- Revert "drm/i915/tgl: Include ro parts of l3 to invalidate" (Mika)
- Fix HDC pipeline flush hardware bit on Gen12 (Mika)
- Flush L3 when flushing render on Gen12 (Mika)
- Invalidate aux table entries forcibly between BB on Gen12 (Mika)
- Add aux table invalidate for all engines on Gen12 (Mika)
- Force pte cacheline to main memory Gen8+ (Mika)
- Add and enable TGL+ SAGV support (Stanislav)
- Implement vm_ops->access on i915 mmaps for GDB (Chris, Kristian)
- Replace zero-length array with flexible-array (Gustavo)
- Improve batch buffer pool effectiveness to mitigate soft-rc6 hit (Chris)
- Remove wait priority boosting (Chris)
- Keep driver module referenced when PMU is active (Chris)
- Sanitize RPS interrupts upon resume (Chris)
- Extend pcode read timeout to 20 ms (Chris)
- Wait for ACT sent before enabling MST pipe (Ville)
- Extend support to async relocations to SNB (Chris)
- Remove CNL pre-prod workarounds (Ville)
- Don't enable WaIncreaseLatencyIPCEnabled when IPC is disabled (Sultan)
- Record the active CCID from before reset (Chris)
- Mark concurrent submissions with a weak-dependency (Chris)
- Peel dma-fence-chains for await to allow engine-to-engine sync (Lionel)
- Prevent using semaphores to chain up to external fences (Chris)
- Fix GLK watermark calculations (Ville)
- Emit await(batch) before MI_BB_START (Chris)
- Reset execlists registers before HWSP (Chris)
- Drop no-semaphore boosting in favor of fast timeslicing (Chris)
- Fix enabled infoframe states of lspcon (Gwan-gyeong)
- Program DP SDPs on pipe updates (Gwan-gyeong)
- Stop sending DP SDPs on ddi disable (Gwan-gyeong)
- Store CS timestamp frequency in Hz (Ville)
- Remove unused HAS_FWTABLE macro (Pascal)
- Use batchbuffer chaining for relocations to save ring space (Chris)
- Try different engines for relocs if MI ops not supported (Chris, Tvrtko)
- Lazily acquire the device wakeref for freeing objects (Chris)
- Streamline display code arithmetics around rounding etc. (Ville)
- Use bw state for per crtc SAGV evaluation (Stanislav)
- Track active_pipes in bw_state (Stanislav)
- Nuke mode.vrefresh usage (Ville)
- Warn if the FBC is still writing to stolen on removal (Chris)
- Added new PCode commands prepping for QGV rescricting (Stansilav)
- Stop holding onto the pinned_default_state (Chris)
- Propagate error from completed fences (Chris)
- Ignore submit-fences on the same timeline (Chris)
- Pull waiting on an external dma-fence into its routine (Chris)
- Replace the hardcoded I915_FENCE_TIMEOUT with Kconfig (Chris)
- Mark up the racy read of execlists->context_tag (Chris)
- Tidy up the return handling for completed dma-fences (Chris)
- Introduce skl_plane_wm_level accessor (Stanislav)
- Extract SKL SAGV checking (Stanislav)
- Make active_pipes check skl specific (Stanislav)
- Suspend tasklets before resume sanitization (Chris)
- Remove redundant exec_fence (Chris)
- Mark the addition of the initial-breadcrumb in the request (Chris)
- Transfer old virtual breadcrumbs to irq_worker (Chris)
- Read the DP SDPs from the video DIP (Gwan-gyeong)
- Program DP SDPs with computed configs (Gwan-gyeong)
- Add state readout for DP VSC and DP HDR Metadata Infoframe SDP
(Gwan-gyeong)
- Add compute routine for DP PSR VSC SDP (Gwan-gyeong)
- Use new DP VSC SDP compute routine on PSR (Gwan-gyeong)
- Restrict qgv points which don't have enough bandwidth. (Stanislav)
- Nuke pointless div by 64bit (Ville)
- Static checker code fixes (Nathan, Mika, Chris)
- Add logging function for DP VSC SDP (Gwan-gyeong)
- Include HDMI DRM infoframe, DP HDR metadata and DP VSC SDP in the
crtc state dump (Gwan-gyeong)
- Make timeslicing explicit engine property (Chris, Tvrtko)
- Selftest and debugging improvements (Chris)
- Align variable names with BSpec (Ville)
- Tidy up gen8+ breadcrumb emission code (Chris)
- Turn intel_digital_port_connected() in a vfunc (Ville)
- Use stashed away hpd isr bits in intel_digital_port_connected() (Ville)
- Extract i915_cs_timestamp_{ns_to_ticks,tick_to_ns}() (Ville)
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200515160703.GA19043@jlahtine-desk.ger.corp.intel.com
When this flag is set in the CS IB flags, it causes
a memory cache flush of the GFX.
v2:
Move new flag to drm_amdgpu_cs_chunk_ib.flags
Bump up UAPI version
Remove condition on job != null to emit mem_sync
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm-misc-next for 5.8:
UAPI Changes:
Cross-subsystem Changes:
* dma-buf: use atomic64_fetch_add() for context id
* Documentation: document bindings for ASUS ZOOT TM5P5, BOE NV133FHM-N62,
hpd-gpios
Core Changes:
Driver Changes:
* drm/ast: fix supend; cleanups
* drm/i2c: cleanups
* drm/panel: add MODULE_LICENSE to panel-visinox-rm69299; add support for
ASUS TM5P5i, BOE NV133FHM-N62i; fix size and bpp of BOE NV133FHM-N61
add hpd-gpio to panel-simple
* drm/mcde: fix return value check in mcde_dsi_bind()
* drm/mgag200: use managed drmm_mode_config_init(); cleanups
* fbdev/pxa168fb: cleanups
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200514070819.GA6930@linux-uq9g
It adds an unpack only function for DRM infoframe for dynamic range and
mastering infoframe readout.
It unpacks the information data block contained in the binary buffer into
a structured frame of the HDMI Dynamic Range and Mastering (DRM)
information frame.
In contrast to hdmi_drm_infoframe_unpack() function, it does not verify
a checksum.
It can be used for unpacking a DP HDR Metadata Infoframe SDP case.
DP HDR Metadata Infoframe SDP uses the same Dynamic Range and Mastering
(DRM) information (CTA-861-G spec.) such as HDMI DRM infoframe.
But DP SDP header and payload structure are different from HDMI DRM
Infoframe. Therefore unpacking DRM infoframe for DP requires skipping of
a verifying checksum.
v9: Add clear comments to hdmi_drm_infoframe_unpack_only() and
hdmi_drm_infoframe_unpack() (Laurent Pinchart)
Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200514060732.3378396-2-gwan-gyeong.mun@intel.com
Make an additional note on DRM format modifiers for x and y tiling. These
format modifiers are defined for BDW+ platforms and therefore definition
is not valid for older gens. This is due to address swizzling for tiled
surfaces is no longer used. For newer platforms main memory controller has
a more effective address swizzling algorithm.
v2: Rephrase comment (Daniel)
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200506120827.12250-1-mika.kahola@intel.com
drm-misc-next for 5.8:
UAPI Changes:
Cross-subsystem Changes:
* MAINTAINERS: restore alphabetical order; update cirrus driver
* Dcomuentation: document visionix, chronteli, ite vendor prefices; update
documentation for Chrontel CH7033, IT6505, IVO, BOE,
Panasonic, Chunghwa, AUO bindings; convert dw_mipi_dsi.txt
to YAML; remove todo item for drm_display_mode.hsync removal;
Core Changes:
* drm: add devm_drm_dev_alloc() for managed allocations of drm_device;
use DRM_MODESET_LOCK_ALL_*() in mode-object code; remove
drm_display_mode.hsync; small cleanups of unused variables,
compiler warnings and static functions
* drm/client: dual-lincensing: GPL-2.0 or MIT
* drm/mm: optimize tree searches in rb_hole_addr()
Driver Changes:
* drm/{many}: use devm_drm_dev_alloc(); don't use drm_device.dev_private
* drm/ast: don't double-assign to drm_crtc_funcs.set_config; drop
drm_connector_register()
* drm/bochs: drop drm_connector_register()
* drm/bridge: add support for Chrontel ch7033; fix stack usage with
old gccs; return error pointer in drm_panel_bridge_add()
* drm/cirrus: Move to tiny
* drm/dp_mst: don't use 2nd sideband tx slot; revert "Remove single tx
msg restriction"
* drm/lima: support runtime PM;
* drm/meson: limit modes wrt chipset
* drm/panel: add support for Visionox rm69299; fix clock on
boe-tv101wum-n16; fix panel type for AUO G101EVN10;
add support for Ivo M133NFW4 R0; add support for BOE
NV133FHM-N61; add support for AUO G121EAN01.4, G156XTN01.0,
G190EAN01
* drm/pl111: improve vexpress init; fix module auto-loading
* drm/stm: read number of endpoints from device tree
* drm/vboxvideo: use managed PCI functions; drop DRM_MTRR_WC
* drm/vkms: fix use-after-free in vkms_gem_create(); enable cursor
support by default
* fbdev: use boolean values in several drivers
* fbdev/controlfb: fix COMPILE_TEST
* fbdev/w100fb: fix double-free bug
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200507072503.GA10979@linux-uq9g
Userspace can severely fragment rb_hole_addr rbtree by manipulating
alignment while allocating buffers. Fragmented rb_hole_addr rbtree
would result in large delays while allocating buffer object for a
userspace application. It takes long time to find suitable hole
because if we fail to find a suitable hole in the first attempt
then we look for neighbouring nodes using rb_prev()/rb_next().
Traversing rbtree using rb_prev()/rb_next() can take really long
time if the tree is fragmented.
This patch improves searches in fragmented rb_hole_addr rbtree by
modifying it to an augmented rbtree which will store an extra field
in drm_mm_node, subtree_max_hole. Each drm_mm_node now stores maximum
hole size for its subtree in drm_mm_node->subtree_max_hole. Using
drm_mm_node->subtree_max_hole, it is possible to eliminate a complete
subtree if that subtree is unable to serve a request hence reducing
number of rb_prev()/rb_next() used.
With this patch applied, 1 million bo allocs on amdgpu took ~8 sec,
compared to 50k bo allocs which took 28 sec without it.
partial test code:
int test_fragmentation(void)
{
int i = 0;
uint32_t minor_version;
uint32_t major_version;
struct amdgpu_bo_alloc_request request = {};
amdgpu_bo_handle vram_handle[MAX_ALLOC] = {};
amdgpu_device_handle device_handle;
request.alloc_size = 4096;
request.phys_alignment = 8192;
request.preferred_heap = AMDGPU_GEM_DOMAIN_VRAM;
int fd = open("/dev/dri/card0", O_RDWR | O_CLOEXEC);
amdgpu_device_initialize(fd, &major_version, &minor_version,
&device_handle);
for (i = 0; i < MAX_ALLOC; i++) {
amdgpu_bo_alloc(device_handle, &request, &vram_handle[i]);
}
for (i = 0; i < MAX_ALLOC; i++)
amdgpu_bo_free(vram_handle[i]);
return 0;
}
v2:
Use RB_DECLARE_CALLBACKS_MAX to maintain subtree_max_hole
v3:
insert_hole_addr() should be static a function
fix return value of next_hole_high_addr()/next_hole_low_addr()
Reported-by: kbuild test robot <lkp@intel.com>
v4:
Fix commit message.
Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/364341/
Signed-off-by: Christian König <christian.koenig@amd.com>
Add a new kfd ioctl to allocate queue GWS. Queue
GWS is released on queue destroy.
v2: re-introduce this API with the following fixes squashed in:
- drm/amdkfd: fix null pointer dereference on dev
- drm/amdkfd: Return proper error code for gws alloc API
- drm/amdkfd: Remove GPU ID in GWS queue creation
Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Add a flag to the command submission IOCTL
structure which when present indicates that this
command submission should be treated as
secure. The kernel driver uses this flag to
determine whether the engine should be
transitioned to secure or unsecure, or the work
can be submitted to a secure queue depending on
the IP.
v3: the flag is now at command submission IOCTL
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Add a flag to the GEM_CREATE ioctl to create encrypted buffers.
Buffers with this flag set will be created with the TMZ bit set
in the PTEs or engines accessing them. This is required in order
to properly access the data from the engines.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Add a new macro helper to combine the usual init sequence in drivers,
consisting of a kzalloc + devm_drm_dev_init + drmm_add_final_kfree
triplet. This allows us to remove the rather unsightly
drmm_add_final_kfree from all currently merged drivers.
The kerneldoc is only added for this new function. Existing kerneldoc
and examples will be udated at the very end, since once all drivers
are converted over to devm_drm_dev_alloc we can unexport a lot of
interim functions and make the documentation for driver authors a lot
cleaner and less confusing. There will be only one true way to
initialize a drm_device at the end of this, which is going to be
devm_drm_dev_alloc.
v2:
- Actually explain what this is for in the commit message (Sam)
- Fix checkpatch issues (Sam)
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Cc: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200415074034.175360-2-daniel.vetter@ffwll.ch
While we support using both tx slots for sideband transmissions, it
appears that DisplayPort devices in the field didn't end up doing a very
good job of supporting it. From section 5.2.1 of the DP 2.0
specification:
There are MST Sink/Branch devices in the field that do not handle
interleaved message transactions.
To facilitate message transaction handling by downstream devices, an
MST Source device shall generate message transactions in an atomic
manner (i.e., the MST Source device shall not concurrently interleave
multiple message transactions). Therefore, an MST Source device shall
clear the Message_Sequence_No value in the Sideband_MSG_Header to 0.
This might come as a bit of a surprise since the vast majority of hubs
will support using both tx slots even if they don't support interleaved
message transactions, and we've also been using both tx slots since MST
was introduced into the kernel.
However, there is one device we've had trouble getting working
consistently with MST for so long that we actually assumed it was just
broken: the infamous Dell P2415Qb. Previously this monitor would appear
to work sometimes, but in most situations would end up timing out
LINK_ADDRESS messages almost at random until you power cycled the whole
display. After reading section 5.2.1 in the DP 2.0 spec, some closer
investigation into this infamous display revealed it was only ever
timing out on sideband messages in the second TX slot.
Sure enough, avoiding the second TX slot has suddenly made this monitor
function perfectly for the first time in five years. And since they
explicitly mention this in the specification, I doubt this is the only
monitor out there with this issue. This might even explain explain the
seemingly harmless garbage sideband responses we would occasionally see
with MST hubs!
So - rewrite our sideband TX handlers to only support one TX slot. In
order to simplify our sideband handling now that we don't support
transmitting to multiple MSTBs at once, we also move all state tracking
for down replies from mstbs to the topology manager.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: ad7f8a1f9c ("drm/helper: add Displayport multi-stream helper (v0.6)")
Cc: Sean Paul <sean@poorly.run>
Cc: "Lin, Wayne" <Wayne.Lin@amd.com>
Cc: <stable@vger.kernel.org> # v3.17+
Reviewed-by: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20200424181308.770749-1-lyude@redhat.com
This reverts commit 6bb0942e8f.
Unfortunately it would appear that the rumors we've heard of sideband
message interleaving not being very well supported are true. On the
Lenovo ThinkPad Thunderbolt 3 dock that I have, interleaved messages
appear to just get dropped:
[drm:drm_dp_mst_wait_tx_reply [drm_kms_helper]] timedout msg send
00000000571ddfd0 2 1
[dp_mst] txmsg cur_offset=2 cur_len=2 seqno=1 state=SENT path_msg=1 dst=00
[dp_mst] type=ENUM_PATH_RESOURCES contents:
[dp_mst] port=2
DP descriptor for this hub:
OUI 90-cc-24 dev-ID SYNA3 HW-rev 1.0 SW-rev 3.12 quirks 0x0008
It would seem like as well that this is a somewhat well known issue in
the field. From section 5.4.2 of the DisplayPort 2.0 specification:
There are MST Sink/Branch devices in the field that do not handle
interleaved message transactions.
To facilitate message transaction handling by downstream devices, an
MST Source device shall generate message transactions in an atomic
manner (i.e., the MST Source device shall not concurrently interleave
multiple message transactions). Therefore, an MST Source device shall
clear the Message_Sequence_No value in the Sideband_MSG_Header to 0.
MST Source devices that support field policy updates by way of
software should update the policy to forego the generation of
interleaved message transactions.
This is a bit disappointing, as features like HDCP require that we send
a sideband request every ~2 seconds for each active stream. However,
there isn't really anything in the specification that allows us to
accurately probe for interleaved messages.
If it ends up being that we -really- need this in the future, we might
be able to whitelist hubs where interleaving is known to work-or maybe
try some sort of heuristics. But for now, let's just play it safe and
not use it.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: 6bb0942e8f ("drm/dp_mst: Remove single tx msg restriction.")
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200423164225.680178-1-lyude@redhat.com
Reviewed-by: Sean Paul <sean@poorly.run>
drm-misc-next for 5.8:
UAPI Changes:
- drm: error out with EBUSY when device has existing master
- drm: rework SET_MASTER and DROP_MASTER perm handling
Cross-subsystem Changes:
- mm: export two symbols from slub/slob
- fbdev: savage: fix -Wextra build warning
- video: omap2: Use scnprintf() for avoiding potential buffer overflow
Core Changes:
- Remove drm_pci.h
- drm_pci_{alloc/free)() are now legacy
- Introduce managed DRM resourcesA
- Allow drivers to subclass struct drm_framebuffer
- Introduce struct drm_afbc_framebuffer and helpers
- fbdev: remove return value from generic fbdev setup
- Introduce simple-encoder helper
- vram-helpers: set fence on plane
- dp_mst: ACT timeout improvements
- dp_mst: Remove drm_dp_mst_has_audio()
- TTM: ttm_trace_dma_{map/unmap}() cleanups
- dma-buf: add flag for PCIP2P support
- EDID: Various improvements
- Encoder: cleanup semantics of possible_clones and possible_crtcs
- VBLANK documentation updates
- Writeback documentation updates
Driver Changes:
- Convert several drivers to i2c_new_client_device()
- Drop explicit drm_mode_config_cleanup() calls from drivers
- Auto-release device structures with drmm_add_final_kfree()
- Init bfdev console after registering DRM device
- Make various .debugfs functions return 0 unconditionally; ignore errors
- video: Use scnprintf() to avoid buffer overflows
- Convert drivers to simple encoders
- drm/amdgpu: note that we can handle peer2peer DMA-buf
- drm/amdgpu: add support for exporting VRAM using DMA-buf v3
- drm/kirin: Revert change to register connectors
- drm/lima: Add optional devfreq and cooling device support
- drm/lima: Various improvements wrt. task handling
- drm/panel: nt39016: Support multiple modes and 50Hz
- drm/panel: Support Leadtek LTK050H3146W
- drm/rockchip: Add support for afbc
- drm/virtio: Various cleanups
- drm/hisilicon/hibmc: Enforce 128-byte stride alignment
- drm/qxl: Fix notify port address of cursor ring buffer
- drm/sun4i: Improvements to format handling
- drm/bridge: dw-hdmi: Various improvements
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200414090738.GA16827@linux-uq9g
UAPI Changes:
- drm/i915/perf: introduce global sseu pinning
Allow userspace to request at perf/OA open full SSEU configuration
on the system to be able to benchmark 3D workloads, at the cost of not
being able to run media workloads. (Lionel)
Userspace changes: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4021
- drm/i915/perf: add new open param to configure polling of OA buffer
Let application choose how often the OA buffer should be checked on
the CPU side for data availability for choosig between CPU overhead
and realtime nature of data.
Userspace changes: https://patchwork.freedesktop.org/series/74655/
(i915 perf recorder is a tool to capture i915 perf data for viewing
in GPUVis.)
- drm/i915/perf: remove generated code
Removal of the machine generated perf/OA test configurations from i915.
Used by Mesa v17.1-18.0, and shortly replaced by userspace supplied OA
configurations. Removal of configs causes affected Mesa versions to
fall back to earlier kernel behaviour (potentially missing metrics).
(Lionel)
Cross-subsystem Changes:
- Backmerge of drm-next
- Includes tag 'topic/phy-compliance-2020-04-08' from
git://anongit.freedesktop.org/drm/drm-misc
Driver Changes:
- Fix for GitLab issue #27: Support 5k tiled dual DP display on SKL (Ville)
- Fix https://github.com/thesofproject/linux/issues/1719: Broken audio after
S3 resume on JSL platforms. (Kai)
- Add new Tigerlake PCI IDs (Swathi D.)
- Add missing Tigerlake W/As (Matt R.)
- Extended Wa_2006604312 to EHL (Matt A)
- Add DPCD link_rate quirk for Apple 15" MBP 2017 (v3) (Mario)
- Make Wa_14010229206 apply to all Tigerlake steppings (Swathi d)
- Extend hotplug detect retry on TypeC connectors to 5 seconds (Imre)
- Yield the timeslice if caught waiting on a user semaphore (Chris)
- Limit the residual W/A batch to Haswell due to instability on IVB/BYT (Chris)
- TBT AUX should use TC power well ops on Tigerlake (Matt R)
- Update PMINTRMSK holding fw to make it effective for RPS (Francisco, Chris)
- Add YUV444 packed format support for skl+ (Stanislav)
- Invalidate OA TLB when closing perf stream to avoid corruption (Umesh)
- HDCP: fix Ri prime check done during link check (Oliver)
- Rearm heartbeat on sysfs interval change (Chris)
- Fix crtc nv12 etc. plane bitmasks for DPMS off (Ville)
- Treat idling as a RPS downclock event (Chris)
- Leave rps->cur_freq on unpark (Chris)
- Ignore short pulse when EDP panel powered off (Anshuman)
- Keep the engine awake until the next jiffie, to avoid ping-pong on
moderate load (Chris)
- Select the deepest available parking mode for rc6 on IVB (Chris)
- Optimizations to direct submission execlist path (Chris)
- Avoid NULL pointer dereference at intel_read_infoframe() (Chris)
- Fix mode private_flags comparison at atomic_check (Uma, Ville)
- Use forced codec wake on all gen9+ platforms (Kai)
- Schedule oa_config after modifying the contexts (Chris, Lionel)
- Explicitly reset both reg and context runtime on GPU reset (Chris)
- Don't enable DDI IO power on a TypeC port in TBT mode (Imre)
- Fixes to TGL, ICL and EHL vswing tables (Jose)
- Fill all the unused space in the GGTT (Chris, imre)
- Ignore readonly failures when updating relocs (Chris)
- Attempt to find free space earlier for non-pinned VMAs (Chris)
- Only wait for GPU activity before unbinding a GGTT fence (Chris)
- Avoid data loss on small userspace perf OA polling (Ashutosh)
- Watch out for unevictable nodes during eviction (Matt A)
- Reinforce the barrier after GTT updates for Ironlake (Chris)
- Convert various parts of driver to use drm_device based logging (Wambui, Jani)
- Avoid dereferencing already closed context for engine (Chris)
- Enable non-contiguous pipe fusing (Anshuman)
- Add HW readout of Gamma LUT on ICL (Swati S.)
- Use explicit flag to mark unreachable intel_context (Chris)
- Cancel a hung context if already closed (Chris)
- Add DP VSC/HDR SDP data structures and write routines (Gwan-gyeong)
- Report context-is-closed prior to pinning at execbuf (Chris)
- Mark timeline->cacheline as destroyed after rcu grace period (Chris)
- Avoid live-lock with i915_vma_parked() (Chris)
- Avoid gem_context->mutex for simple vma lookup (Chris)
- Rely on direct submission to the queue (Chris)
- Configure DSI transcoder to operate in TE GATE command mode (Vandita)
- Add DI vblank calculation for command mode (Vandita)
- Disable periodic command mode if programmed by GOP (Vandita)
- Use private flags to indicate TE in cmd mode (Vandita)
- Make fences a nice-to-have for FBC on GEN9+ (Jose)
- Fix work queuing issue with mixed virtual engine/physical engine
submissions (Chris)
- Drop final few uses of drm_i915_private.engine (Chris)
- Return early after MISSING_CASE for write_dp_sdp (Chris)
- Include port sync state in the state dump (Ville)
- ELSP workaround switching back to a completed context (Chris)
- Include priority info in trace_ports (Chris)
- Allow for different modes of interruptible i915_active_wait (Chris)
- Split eb_vma into its own allocation (Chris)
- Don't read perf head/tail pointers outside critical section (Lionel)
- Pause CS flow before execlists reset (Chris)
- Make fence revocation unequivocal (Chris)
- Drop cached obj->bind_count (Chris)
- Peek at the next submission for error interrupts (Chris)
- Utilize rcu iteration of context engines (Chris)
- Keep a per-engine request pool for power management ops (Chris)
- Refactor port sync code into normal modeset flow (Ville)
- Check current i915_vma.pin_count status first on unbind (Chris)
- Free request pool from virtual engines (Chris)
- Flush all the reloc_gpu batch (Chris)
- Make exclusive awaits on i915_active optional and allow async waits (Chris)
- Wait until the context is finally retired before releasing engines (Chris)
- Prefer '%ps' for printing function symbol names (Chris)
- Allow setting generic data pointer on intel GT debugfs (Andi)
- Constify DP link computation code more (Ville)
- Simplify MST master transcoder computation (Ville)
- Move TRANS_DDI_FUNC_CTL2 programming where it belongs (Ville)
- Move icl_get_trans_port_sync_config() into the DDI code (Ville)
- Add definitions for VRR registers and bits (Aditya)
- Refactor hardware fence code (Chris)
- Start passing latency as parameter to WM calculation (Stanislav)
- Kernel selftest and debug tracing improvements (Matt A, Chris, Mika)
- Fixes to CI found corner cases and lockdep splats (Chris)
- Overall fixes and refactoring to GEM code (Chris)
- Overall fixes and refactoring to display code (Ville)
- GuC/HuC code improvements (Daniele, Michal Wa)
- Static code checker fixes (Nathan, Ville, Colin, Chris)
- Fix spelling mistake (Chen)
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200417111548.GA15033@jlahtine-desk.ger.corp.intel.com
Pull irq fixes from Thomas Gleixner:
"A set of fixes/updates for the interrupt subsystem:
- Remove setup_irq() and remove_irq(). All users have been converted
so remove them before new users surface.
- A set of bugfixes for various interrupt chip drivers
- Add a few missing static attributes to address sparse warnings"
* tag 'irq-urgent-2020-04-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/irq-bcm7038-l1: Make bcm7038_l1_of_init() static
irqchip/irq-mvebu-icu: Make legacy_bindings static
irqchip/meson-gpio: Fix HARDIRQ-safe -> HARDIRQ-unsafe lock order
irqchip/sifive-plic: Fix maximum priority threshold value
irqchip/ti-sci-inta: Fix processing of masked irqs
irqchip/mbigen: Free msi_desc on device teardown
irqchip/gic-v4.1: Update effective affinity of virtual SGIs
irqchip/gic-v4.1: Add support for VPENDBASER's Dirty+Valid signaling
genirq: Remove setup_irq() and remove_irq()
Pull ext4 fixes from Ted Ts'o:
"Miscellaneous bug fixes and cleanups for ext4, including a fix for
generic/388 in data=journal mode, removing some BUG_ON's, and cleaning
up some compiler warnings"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: convert BUG_ON's to WARN_ON's in mballoc.c
ext4: increase wait time needed before reuse of deleted inode numbers
ext4: remove set but not used variable 'es' in ext4_jbd2.c
ext4: remove set but not used variable 'es'
ext4: do not zeroout extents beyond i_disksize
ext4: fix return-value types in several function comments
ext4: use non-movable memory for superblock readahead
ext4: use matching invalidatepage in ext4_writepage
Pull flexible-array member conversion from Gustavo Silva:
"The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array
member[1][2], introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof
operator may not be applied. As a quirk of the original
implementation of zero-length arrays, sizeof evaluates to zero."[1]
sizeof(flexible-array-member) triggers a warning because flexible
array members have incomplete type[1]. There are some instances of
code in which the sizeof operator is being incorrectly/erroneously
applied to zero-length arrays and the result is zero. Such instances
may be hiding some bugs. So, this work (flexible-array member
convertions) will also help to get completely rid of those sorts of
issues.
Notice that all of these patches have been baking in linux-next for
quite a while now and, 238 more of these patches have already been
merged into 5.7-rc1.
There are a couple hundred more of these issues waiting to be
addressed in the whole codebase"
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
* tag 'flexible-array-member-5.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (28 commits)
xattr.h: Replace zero-length array with flexible-array member
uapi: linux: fiemap.h: Replace zero-length array with flexible-array member
uapi: linux: dlm_device.h: Replace zero-length array with flexible-array member
tpm_eventlog.h: Replace zero-length array with flexible-array member
ti_wilink_st.h: Replace zero-length array with flexible-array member
swap.h: Replace zero-length array with flexible-array member
skbuff.h: Replace zero-length array with flexible-array member
sched: topology.h: Replace zero-length array with flexible-array member
rslib.h: Replace zero-length array with flexible-array member
rio.h: Replace zero-length array with flexible-array member
posix_acl.h: Replace zero-length array with flexible-array member
platform_data: wilco-ec.h: Replace zero-length array with flexible-array member
memcontrol.h: Replace zero-length array with flexible-array member
list_lru.h: Replace zero-length array with flexible-array member
lib: cpu_rmap: Replace zero-length array with flexible-array member
irq.h: Replace zero-length array with flexible-array member
ihex.h: Replace zero-length array with flexible-array member
igmp.h: Replace zero-length array with flexible-array member
genalloc.h: Replace zero-length array with flexible-array member
ethtool.h: Replace zero-length array with flexible-array member
...
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
