====================
pull-request: bpf-next 2023-04-13
We've added 260 non-merge commits during the last 36 day(s) which contain
a total of 356 files changed, 21786 insertions(+), 11275 deletions(-).
The main changes are:
1) Rework BPF verifier log behavior and implement it as a rotating log
by default with the option to retain old-style fixed log behavior,
from Andrii Nakryiko.
2) Adds support for using {FOU,GUE} encap with an ipip device operating
in collect_md mode and add a set of BPF kfuncs for controlling encap
params, from Christian Ehrig.
3) Allow BPF programs to detect at load time whether a particular kfunc
exists or not, and also add support for this in light skeleton,
from Alexei Starovoitov.
4) Optimize hashmap lookups when key size is multiple of 4,
from Anton Protopopov.
5) Enable RCU semantics for task BPF kptrs and allow referenced kptr
tasks to be stored in BPF maps, from David Vernet.
6) Add support for stashing local BPF kptr into a map value via
bpf_kptr_xchg(). This is useful e.g. for rbtree node creation
for new cgroups, from Dave Marchevsky.
7) Fix BTF handling of is_int_ptr to skip modifiers to work around
tracing issues where a program cannot be attached, from Feng Zhou.
8) Migrate a big portion of test_verifier unit tests over to
test_progs -a verifier_* via inline asm to ease {read,debug}ability,
from Eduard Zingerman.
9) Several updates to the instruction-set.rst documentation
which is subject to future IETF standardization
(https://lwn.net/Articles/926882/), from Dave Thaler.
10) Fix BPF verifier in the __reg_bound_offset's 64->32 tnum sub-register
known bits information propagation, from Daniel Borkmann.
11) Add skb bitfield compaction work related to BPF with the overall goal
to make more of the sk_buff bits optional, from Jakub Kicinski.
12) BPF selftest cleanups for build id extraction which stand on its own
from the upcoming integration work of build id into struct file object,
from Jiri Olsa.
13) Add fixes and optimizations for xsk descriptor validation and several
selftest improvements for xsk sockets, from Kal Conley.
14) Add BPF links for struct_ops and enable switching implementations
of BPF TCP cong-ctls under a given name by replacing backing
struct_ops map, from Kui-Feng Lee.
15) Remove a misleading BPF verifier env->bypass_spec_v1 check on variable
offset stack read as earlier Spectre checks cover this,
from Luis Gerhorst.
16) Fix issues in copy_from_user_nofault() for BPF and other tracers
to resemble copy_from_user_nmi() from safety PoV, from Florian Lehner
and Alexei Starovoitov.
17) Add --json-summary option to test_progs in order for CI tooling to
ease parsing of test results, from Manu Bretelle.
18) Batch of improvements and refactoring to prep for upcoming
bpf_local_storage conversion to bpf_mem_cache_{alloc,free} allocator,
from Martin KaFai Lau.
19) Improve bpftool's visual program dump which produces the control
flow graph in a DOT format by adding C source inline annotations,
from Quentin Monnet.
20) Fix attaching fentry/fexit/fmod_ret/lsm to modules by extracting
the module name from BTF of the target and searching kallsyms of
the correct module, from Viktor Malik.
21) Improve BPF verifier handling of '<const> <cond> <non_const>'
to better detect whether in particular jmp32 branches are taken,
from Yonghong Song.
22) Allow BPF TCP cong-ctls to write app_limited of struct tcp_sock.
A built-in cc or one from a kernel module is already able to write
to app_limited, from Yixin Shen.
Conflicts:
Documentation/bpf/bpf_devel_QA.rst
b7abcd9c65 ("bpf, doc: Link to submitting-patches.rst for general patch submission info")
0f10f647f4 ("bpf, docs: Use internal linking for link to netdev subsystem doc")
https://lore.kernel.org/all/20230307095812.236eb1be@canb.auug.org.au/
include/net/ip_tunnels.h
bc9d003dc4 ("ip_tunnel: Preserve pointer const in ip_tunnel_info_opts")
ac931d4cde ("ipip,ip_tunnel,sit: Add FOU support for externally controlled ipip devices")
https://lore.kernel.org/all/20230413161235.4093777-1-broonie@kernel.org/
net/bpf/test_run.c
e5995bc7e2 ("bpf, test_run: fix crashes due to XDP frame overwriting/corruption")
294635a816 ("bpf, test_run: fix &xdp_frame misplacement for LIVE_FRAMES")
https://lore.kernel.org/all/20230320102619.05b80a98@canb.auug.org.au/
====================
Link: https://lore.kernel.org/r/20230413191525.7295-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
During warm reset device->fw_client is set to NULL. If a bus driver is
registered after this NULL setting and before new firmware clients are
enumerated by ISHTP, kernel panic will result in the function
ishtp_cl_bus_match(). This is because of reference to
device->fw_client->props.protocol_name.
ISH firmware after getting successfully loaded, sends a warm reset
notification to remove all clients from the bus and sets
device->fw_client to NULL. Until kernel v5.15, all enabled ISHTP kernel
module drivers were loaded right after any of the first ISHTP device was
registered, regardless of whether it was a matched or an unmatched
device. This resulted in all drivers getting registered much before the
warm reset notification from ISH.
Starting kernel v5.16, this issue got exposed after the change was
introduced to load only bus drivers for the respective matching devices.
In this scenario, cros_ec_ishtp device and cros_ec_ishtp driver are
registered after the warm reset device fw_client NULL setting.
cros_ec_ishtp driver_register() triggers the callback to
ishtp_cl_bus_match() to match ISHTP driver to the device and causes kernel
panic in guid_equal() when dereferencing fw_client NULL pointer to get
protocol_name.
Fixes: f155dfeaa4 ("platform/x86: isthp_eclite: only load for matching devices")
Fixes: facfe0a4fd ("platform/chrome: chros_ec_ishtp: only load for matching devices")
Fixes: 0d0cccc0fd ("HID: intel-ish-hid: hid-client: only load for matching devices")
Fixes: 44e2a58cb8 ("HID: intel-ish-hid: fw-loader: only load for matching devices")
Cc: <stable@vger.kernel.org> # 5.16+
Signed-off-by: Tanu Malhotra <tanu.malhotra@intel.com>
Tested-by: Shaunak Saha <shaunak.saha@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
On some platforms there are some platform devices created with
invalid names. For example: "HID-SENSOR-INT-020b?.39.auto" instead
of "HID-SENSOR-INT-020b.39.auto"
This string include some invalid characters, hence it will fail to
properly load the driver which will handle this custom sensor. Also
it is a problem for some user space tools, which parses the device
names from ftrace and dmesg.
This is because the string, real_usage, is not NULL terminated and
printed with %s to form device name.
To address this, initialize the real_usage string with 0s.
Reported-and-tested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217169
Fixes: 98c062e824 ("HID: hid-sensor-custom: Allow more custom iio sensors")
Cc: stable@vger.kernel.org
Suggested-by: Philipp Jungkamp <p.jungkamp@gmx.net>
Signed-off-by: Philipp Jungkamp <p.jungkamp@gmx.net>
Signed-off-by: Todd Brandt <todd.e.brandt@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The tenkeyless version of the Realforce R2 has the same issue of the
full size one, the report fixup is needed to make n-key rollover
work instead of 6 key rollover
Signed-off-by: Alessandro Manca <crizan.git@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Similar to many other devices using the Synopsys Designware Elantech
hardware, HP Spectre x360 13t-aw100 and 14t-ea100 report an empty
battery devices, supposedly for the active stylus.
Apply the HID_BATTERY_QUIRK_IGNORE quirk to ignore the battery reports
from these devices. Note that there are multiple versions of the panel
installed in the 14t-ea100.
Signed-off-by: Philippe Troin <phil@fifi.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Pull HID fixes from Benjamin Tissoires:
- fix potential out of bound write of zeroes in HID core with a
specially crafted uhid device (Lee Jones)
- fix potential use-after-free in work function in intel-ish-hid (Reka
Norman)
- selftests config fixes (Benjamin Tissoires)
- few device small fixes and support
* tag 'for-linus-2023030901' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
HID: intel-ish-hid: ipc: Fix potential use-after-free in work function
HID: logitech-hidpp: Add support for Logitech MX Master 3S mouse
HID: cp2112: Fix driver not registering GPIO IRQ chip as threaded
selftest: hid: fix hid_bpf not set in config
HID: uhid: Over-ride the default maximum data buffer value with our own
HID: core: Provide new max_buffer_size attribute to over-ride the default
When a reset notify IPC message is received, the ISR schedules a work
function and passes the ISHTP device to it via a global pointer
ishtp_dev. If ish_probe() fails, the devm-managed device resources
including ishtp_dev are freed, but the work is not cancelled, causing a
use-after-free when the work function tries to access ishtp_dev. Use
devm_work_autocancel() instead, so that the work is automatically
cancelled if probe fails.
Signed-off-by: Reka Norman <rekanorman@chromium.org>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Pull driver core updates from Greg KH:
"Here is the large set of driver core changes for 6.3-rc1.
There's a lot of changes this development cycle, most of the work
falls into two different categories:
- fw_devlink fixes and updates. This has gone through numerous review
cycles and lots of review and testing by lots of different devices.
Hopefully all should be good now, and Saravana will be keeping a
watch for any potential regression on odd embedded systems.
- driver core changes to work to make struct bus_type able to be
moved into read-only memory (i.e. const) The recent work with Rust
has pointed out a number of areas in the driver core where we are
passing around and working with structures that really do not have
to be dynamic at all, and they should be able to be read-only
making things safer overall. This is the contuation of that work
(started last release with kobject changes) in moving struct
bus_type to be constant. We didn't quite make it for this release,
but the remaining patches will be finished up for the release after
this one, but the groundwork has been laid for this effort.
Other than that we have in here:
- debugfs memory leak fixes in some subsystems
- error path cleanups and fixes for some never-able-to-be-hit
codepaths.
- cacheinfo rework and fixes
- Other tiny fixes, full details are in the shortlog
All of these have been in linux-next for a while with no reported
problems"
[ Geert Uytterhoeven points out that that last sentence isn't true, and
that there's a pending report that has a fix that is queued up - Linus ]
* tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (124 commits)
debugfs: drop inline constant formatting for ERR_PTR(-ERROR)
OPP: fix error checking in opp_migrate_dentry()
debugfs: update comment of debugfs_rename()
i3c: fix device.h kernel-doc warnings
dma-mapping: no need to pass a bus_type into get_arch_dma_ops()
driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct place
Revert "driver core: add error handling for devtmpfs_create_node()"
Revert "devtmpfs: add debug info to handle()"
Revert "devtmpfs: remove return value of devtmpfs_delete_node()"
driver core: cpu: don't hand-override the uevent bus_type callback.
devtmpfs: remove return value of devtmpfs_delete_node()
devtmpfs: add debug info to handle()
driver core: add error handling for devtmpfs_create_node()
driver core: bus: update my copyright notice
driver core: bus: add bus_get_dev_root() function
driver core: bus: constify bus_unregister()
driver core: bus: constify some internal functions
driver core: bus: constify bus_get_kset()
driver core: bus: constify bus_register/unregister_notifier()
driver core: remove private pointer from struct bus_type
...
The CP2112 generates interrupts from a polling routine on a thread,
and can only support threaded interrupts. This patch configures the
gpiochip irq chip with this flag, disallowing consumers to request
a hard IRQ from this driver, which resulted in a segfault previously.
Signed-off-by: Danny Kaehn <kaehndan@gmail.com>
Link: https://lore.kernel.org/r/20230210170044.11835-1-kaehndan@gmail.com
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
The default maximum data buffer size for this interface is UHID_DATA_MAX
(4k). When data buffers are being processed, ensure this value is used
when ensuring the sanity, rather than a value between the user provided
value and HID_MAX_BUFFER_SIZE (16k).
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Presently, when a report is processed, its proposed size, provided by
the user of the API (as Report Size * Report Count) is compared against
the subsystem default HID_MAX_BUFFER_SIZE (16k). However, some
low-level HID drivers allocate a reduced amount of memory to their
buffers (e.g. UHID only allocates UHID_DATA_MAX (4k) buffers), rending
this check inadequate in some cases.
In these circumstances, if the received report ends up being smaller
than the proposed report size, the remainder of the buffer is zeroed.
That is, the space between sizeof(csize) (size of the current report)
and the rsize (size proposed i.e. Report Size * Report Count), which can
be handled up to HID_MAX_BUFFER_SIZE (16k). Meaning that memset()
shoots straight past the end of the buffer boundary and starts zeroing
out in-use values, often resulting in calamity.
This patch introduces a new variable into 'struct hid_ll_driver' where
individual low-level drivers can over-ride the default maximum value of
HID_MAX_BUFFER_SIZE (16k) with something more sympathetic to the
interface.
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Pull HID updates from Benjamin Tissoires:
- HID-BPF infrastructure: this allows to start using HID-BPF. Note that
the mechanism to ship HID-BPF program through the kernel tree is
still not implemented yet (but is planned).
This should be a no-op for 99% of users. Also we are gaining
kselftests for the HID tree (Benjamin Tissoires)
- Some UAF fixes in workers when using uhid (Pietro Borrello & Benjamin
Tissoires)
- Constify hid_ll_driver (Thomas Weißschuh)
- Allow more custom IIO sensors through HID (Philipp Jungkamp)
- Logitech HID++ fixes for scroll wheel, protocol and debug (Bastien
Nocera)
- Some new device support: Steam Deck (Vicki Pfau), UClogic (José
Expósito), Logitech G923 Xbox Edition steering wheel (Walt Holman),
EVision keyboards (Philippe Valembois)
- other assorted code cleanups and fixes
* tag 'for-linus-2023022201' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid: (99 commits)
HID: mcp-2221: prevent UAF in delayed work
hid: bigben_probe(): validate report count
HID: asus: use spinlock to safely schedule workers
HID: asus: use spinlock to protect concurrent accesses
HID: bigben: use spinlock to safely schedule workers
HID: bigben_worker() remove unneeded check on report_field
HID: bigben: use spinlock to protect concurrent accesses
HID: logitech-hidpp: Add myself to authors
HID: logitech-hidpp: Retry commands when device is busy
HID: logitech-hidpp: Add more debug statements
HID: Add support for Logitech G923 Xbox Edition steering wheel
HID: logitech-hidpp: Add Signature M650
HID: logitech-hidpp: Remove HIDPP_QUIRK_NO_HIDINPUT quirk
HID: logitech-hidpp: Don't restart communication if not necessary
HID: logitech-hidpp: Add constants for HID++ 2.0 error codes
Revert "HID: logitech-hidpp: add a module parameter to keep firmware gestures"
HID: logitech-hidpp: Hard-code HID++ 1.0 fast scroll support
HID: i2c-hid: goodix: Add mainboard-vddio-supply
dt-bindings: HID: i2c-hid: goodix: Add mainboard-vddio-supply
HID: i2c-hid: goodix: Stop tying the reset line to the regulator
...
Initial support of HID-BPF (Benjamin Tissoires)
The history is a little long for this series, as it was intended to be
sent for v6.2. However some last minute issues forced us to postpone it
to v6.3.
Conflicts:
* drivers/hid/i2c-hid/Kconfig:
commit bf7660dab3 ("HID: stop drivers from selecting CONFIG_HID")
conflicts with commit 2afac81dd1 ("HID: fix I2C_HID not selected
when I2C_HID_OF_ELAN is")
the resolution is simple enough: just drop the "default" and "select"
lines as the new commit from Arnd is doing
- dev_dbg cleanup (Thomas Weißschuh)
- cleanup i2c-hid-acpi (Andy Shevchenko)
- goodix: revert/fixes for an actual production device compared to the
manufacturer sample (Douglas Anderson)
- constify hid_ll_driver (Thomas Weißschuh)
- map standard Battery System Charging to upower (José Expósito)
- couple of assorted fixes and new handling of HID usages (Jingyuan
Liang & Ronald Tschalär)
Pull x86 platform driver updates from Hans de Goede:
- AMD PMC: Improvements to aid s2idle debugging
- Dell WMI-DDV: hwmon support
- INT3472 camera sensor power-management: Improve privacy LED support
- Intel VSEC: Base TPMI (Topology Aware Register and PM Capsule
Interface) support
- Mellanox: SN5600 and Nvidia L1 switch support
- Microsoft Surface Support: Various cleanups + code improvements
- tools/intel-speed-select: Various improvements
- Miscellaneous other cleanups / fixes
* tag 'platform-drivers-x86-v6.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (80 commits)
platform/x86: nvidia-wmi-ec-backlight: Add force module parameter
platform/x86/amd/pmf: Add depends on CONFIG_POWER_SUPPLY
platform/x86: dell-ddv: Prefer asynchronous probing
platform/x86: dell-ddv: Add hwmon support
Documentation/ABI: Add new attribute for mlxreg-io sysfs interfaces
platform: mellanox: mlx-platform: Move bus shift assignment out of the loop
platform: mellanox: mlx-platform: Add mux selection register to regmap
platform_data/mlxreg: Add field with mapped resource address
platform/mellanox: mlxreg-hotplug: Allow more flexible hotplug events configuration
platform: mellanox: Extend all systems with I2C notification callback
platform: mellanox: Split logic in init and exit flow
platform: mellanox: Split initialization procedure
platform: mellanox: Introduce support of new Nvidia L1 switch
platform: mellanox: Introduce support for next-generation 800GB/s switch
platform: mellanox: Cosmetic changes - rename to more common name
platform: mellanox: Change "reset_pwr_converter_fail" attribute
platform: mellanox: Introduce support for rack manager switch
MAINTAINERS: dell-wmi-sysman: drop Divya Bharathi
x86/platform/uv: Make kobj_type structure constant
platform/x86: think-lmi: Make kobj_type structure constant
...
Pull hyperv updates from Wei Liu:
- allow Linux to run as the nested root partition for Microsoft
Hypervisor (Jinank Jain and Nuno Das Neves)
- clean up the return type of callback functions (Dawei Li)
* tag 'hyperv-next-signed-20230220' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
x86/hyperv: Fix hv_get/set_register for nested bringup
Drivers: hv: Make remove callback of hyperv driver void returned
Drivers: hv: Enable vmbus driver for nested root partition
x86/hyperv: Add an interface to do nested hypercalls
Drivers: hv: Setup synic registers in case of nested root partition
x86/hyperv: Add support for detecting nested hypervisor
If the device is plugged/unplugged without giving time for mcp_init_work()
to complete, we might kick in the devm free code path and thus have
unavailable struct mcp_2221 while in delayed work.
Canceling the delayed_work item is enough to solve the issue, because
cancel_delayed_work_sync will prevent the work item to requeue itself.
Fixes: 960f9df7c6 ("HID: mcp2221: add ADC/DAC support via iio subsystem")
CC: stable@vger.kernel.org
Acked-by: Jiri Kosina <jkosina@suse.cz>
Link: https://lore.kernel.org/r/20230215-wip-mcp2221-v2-1-109f71fd036e@redhat.com
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
bigben_probe() does not validate that the output report has the
needed report values in the first field.
A malicious device registering a report with one field and a single
value causes an head OOB write in bigben_worker() when
accessing report_field->value[1] to report_field->value[7].
Use hid_validate_values() which takes care of all the needed checks.
Fixes: 256a90ed9e ("HID: hid-bigbenff: driver for BigBen Interactive PS3OFMINIPAD gamepad")
Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it>
Link: https://lore.kernel.org/r/20230211-bigben-oob-v1-1-d2849688594c@diag.uniroma1.it
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
bigben_worker() checks report_field to be non-NULL.
The check has been added in commit
918aa1ef10 ("HID: bigbenff: prevent null pointer dereference")
to prevent a NULL pointer crash.
However, the true root cause was a missing check for output
reports, patched in commit
c7bf714f87 ("HID: check empty report_list in bigben_probe()"),
where the type-confused report list_entry was overlapping with
a NULL pointer, which was then causing the crash.
Fixes: 918aa1ef10 ("HID: bigbenff: prevent null pointer dereference")
Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it>
Link: https://lore.kernel.org/r/20230125-hid-unregister-leds-v4-2-7860c5763c38@diag.uniroma1.it
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Handle the busy error coming from the device or receiver. The
documentation says a busy error can be returned when:
"
Device (or receiver) cannot answer immediately to this request
for any reason i.e:
- already processing a request from the same or another SW
- pipe full
"
Signed-off-by: Bastien Nocera <hadess@hadess.net>
Link: https://lore.kernel.org/r/20230209154916.462158-1-hadess@hadess.net
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
HIDPP_QUIRK_NO_HIDINPUT isn't used by any devices but still happens to
work as HIDPP_QUIRK_DELAYED_INIT is defined to the same value. Remove
HIDPP_QUIRK_NO_HIDINPUT and use HIDPP_QUIRK_DELAYED_INIT everywhere
instead.
Tested on a T650 which requires that quirk, and a number of unifying and
Bluetooth devices that don't.
Signed-off-by: Bastien Nocera <hadess@hadess.net>
Link: https://lore.kernel.org/r/20230125121723.3122-2-hadess@hadess.net
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Now that we're in 2022, and the majority of desktop environments can and
should support touchpad gestures through libinput, remove the legacy
module parameter that made it possible to use gestures implemented in
firmware.
This will eventually allow simplifying the driver's initialisation code.
This reverts commit 9188dbaed6.
Signed-off-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20221220154345.474596-1-hadess@hadess.net
Pull HID fixes from Benjamin Tissoires:
- fix potential infinite loop with a badly crafted HID device (Xin
Zhao)
- fix regression from 6.1 in USB logitech devices potentially making
their mouse wheel not working (Bastien Nocera)
- clean up in AMD sensors, which fixes a long time resume bug (Mario
Limonciello)
- few device small fixes and quirks
* tag 'for-linus-2023020901' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
HID: Ignore battery for ELAN touchscreen 29DF on HP
HID: amd_sfh: if no sensors are enabled, clean up
HID: logitech: Disable hi-res scrolling on USB
HID: core: Fix deadloop in hid_apply_multiplier.
HID: Ignore battery for Elan touchscreen on Asus TP420IA
HID: elecom: add support for TrackBall 056E:011C
In commit 18eeef46d3 ("HID: i2c-hid: goodix: Tie the reset line to
true state of the regulator"), we started tying the reset line of
Goodix touchscreens to the regulator.
The primary motivation for that patch was some pre-production hardware
(specifically sc7180-trogdor-homestar) where it was proposed to hook
the touchscreen's main 3.3V power rail to an always-on supply. In such
a case, when we turned "off" the touchscreen in Linux it was bad to
assert the "reset" GPIO because that was causing a power drain. The
patch accomplished that goal and did it in a general sort of way that
didn't require special properties to be added in the device tree for
homestar.
It turns out that the design of using an always-on power rail for the
touchscreen was rejected soon after the patch was written and long
before sc7180-trogdor-homestar went into production. The final design
of homestar actually fully separates the rail for the touchscreen and
the display panel and both can be powered off and on. That means that
the original motivation for the feature is gone.
There are 3 other users of the goodix i2c-hid driver in mainline.
I'll first talk about 2 of the other users in mainline: coachz and
mrbland. On both coachz and mrbland the touchscreen power and panel
power _are_ shared. That means that the patch to tie the reset line to
the true state of the regulator _is_ doing something on those
boards. Specifically, the patch reduced power consumption by tens of
mA in the case where we turned the touchscreen off but left the panel
on. Other than saving a small bit of power, the patch wasn't truly
necessary. That being said, even though a small bit of power was saved
in the state of "panel on + touchscreen off", that's not actually a
state we ever expect to be in, except perhaps for very short periods
of time at boot or during suspend/resume. Thus, the patch is truly not
necessary. It should be further noted that, as documented in the
original patch, the current code still didn't optimize power for every
corner case of the "shared rail" situation.
The last user in mainline was very recently added: evoker. Evoker is
actually the motivation for me removing this bit of code. It turns out
that for evoker we need to manage a second power rail for IO to the
touchscreen. Trying to fit the management of this IO rail into the
regulator notifiers turns out to be extremely hard. To avoid lockdep
splats you shouldn't enable/disable other regulators in regulator
notifiers and trying to find a way around this was going to be fairly
difficult.
Given the lack of any true motivation to tie the reset line to the
regulator, lets go back to the simpler days and remove the code. This
is, effectively, a revert of commit bdbc65eb77ee ("HID: i2c-hid:
goodix: Fix a lockdep splat"), commit 25ddd7cfc5 ("HID: i2c-hid:
goodix: Use the devm variant of regulator_register_notifier()"), and
commit 18eeef46d3 ("HID: i2c-hid: goodix: Tie the reset line to true
state of the regulator").
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://lore.kernel.org/r/20230206184744.4.I085b32b6140c7d1ac4e7e97b712bff9dd5962b62@changeid
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
