In the x86 MM code we'd like to untangle various types of historic
header dependency spaghetti, but for this we'd need to pass to
the generic vmalloc code various vmalloc related defines that
customarily come via the <asm/page.h> low level arch header.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch introduces a sysctl knob "net.ipv4.tcp_no_ssthresh_metrics_save"
that disables TCP ssthresh metrics cache by default. Other parts of TCP
metrics cache, e.g. rtt, cwnd, remain unchanged.
As modern networks becoming more and more dynamic, TCP metrics cache
today often causes more harm than benefits. For example, the same IP
address is often shared by different subscribers behind NAT in residential
networks. Even if the IP address is not shared by different users,
caching the slow-start threshold of a previous short flow using loss-based
congestion control (e.g. cubic) often causes the future longer flows of
the same network path to exit slow-start prematurely with abysmal
throughput.
Caching ssthresh is very risky and can lead to terrible performance.
Therefore it makes sense to make disabling ssthresh caching by
default and opt-in for specific networks by the administrators.
This practice also has worked well for several years of deployment with
CUBIC congestion control at Google.
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Kevin(Yudong) Yang <yyd@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
According to the public S805 datasheet the RESET2 register uses the
following bits for the PIC_DC, PSC and NAND reset lines:
- PIC_DC is at bit 3 (meaning: RESET_VD_RMEM + 3)
- PSC is at bit 4 (meaning: RESET_VD_RMEM + 4)
- NAND is at bit 5 (meaning: RESET_VD_RMEM + 4)
Update the reset IDs of these three reset lines so they don't conflict
with PIC_DC and map to the actual hardware reset lines.
Fixes: 79795e20a1 ("dt-bindings: reset: Add bindings for the Meson SoC Reset Controller")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Implement a SELinux hook for lockdown. If the lockdown module is also
enabled, then a denial by the lockdown module will take precedence over
SELinux, so SELinux can only further restrict lockdown decisions.
The SELinux hook only distinguishes at the granularity of integrity
versus confidentiality similar to the lockdown module, but includes the
full lockdown reason as part of the audit record as a hint in diagnosing
what triggered the denial. To support this auditing, move the
lockdown_reasons[] string array from being private to the lockdown
module to the security framework so that it can be used by the lsm audit
code and so that it is always available even when the lockdown module
is disabled.
Note that the SELinux implementation allows the integrity and
confidentiality reasons to be controlled independently from one another.
Thus, in an SELinux policy, one could allow operations that specify
an integrity reason while blocking operations that specify a
confidentiality reason. The SELinux hook implementation is
stricter than the lockdown module in validating the provided reason value.
Sample AVC audit output from denials:
avc: denied { integrity } for pid=3402 comm="fwupd"
lockdown_reason="/dev/mem,kmem,port" scontext=system_u:system_r:fwupd_t:s0
tcontext=system_u:system_r:fwupd_t:s0 tclass=lockdown permissive=0
avc: denied { confidentiality } for pid=4628 comm="cp"
lockdown_reason="/proc/kcore access"
scontext=unconfined_u:unconfined_r:test_lockdown_integrity_t:s0-s0:c0.c1023
tcontext=unconfined_u:unconfined_r:test_lockdown_integrity_t:s0-s0:c0.c1023
tclass=lockdown permissive=0
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
[PM: some merge fuzz do the the perf hooks]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net:
1) Wait for rcu grace period after releasing netns in ctnetlink,
from Florian Westphal.
2) Incorrect command type in flowtable offload ndo invocation,
from wenxu.
3) Incorrect callback type in flowtable offload flow tuple
updates, also from wenxu.
4) Fix compile warning on flowtable offload infrastructure due to
possible reference to uninitialized variable, from Nathan Chancellor.
5) Do not inline nf_ct_resolve_clash(), this is called from slow
path / stress situations. From Florian Westphal.
6) Missing IPv6 flow selector description in flowtable offload.
7) Missing check for NETDEV_UNREGISTER in nf_tables offload
infrastructure, from wenxu.
8) Update NAT selftest to use randomized netns names, from
Florian Westphal.
9) Restore nfqueue bridge support, from Marco Oliverio.
10) Compilation warning in SCTP_CHUNKMAP_*() on xt_sctp header.
From Phil Sutter.
11) Fix bogus lookup/get match for non-anonymous rbtree sets.
12) Missing netlink validation for NFT_SET_ELEM_INTERVAL_END
elements.
13) Missing netlink validation for NFT_DATA_VALUE after
nft_data_init().
14) If rule specifies no actions, offload infrastructure returns
EOPNOTSUPP.
15) Module refcount leak in object updates.
16) Missing sanitization for ARP traffic from br_netfilter, from
Eric Dumazet.
17) Compilation breakage on big-endian due to incorrect memcpy()
size in the flowtable offload infrastructure.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Panels often support backlight as specified in a device tree.
Update the drm_panel infrastructure to support this to
simplify the drivers.
With this the panel driver just needs to add the following to the
probe() function:
err = drm_panel_of_backlight(panel);
if (err)
return err;
Then drm_panel will handle all the rest.
There is one caveat with the backlight support.
If drm_panel_(enable|disable) are called multiple times
in a row then backlight_(enable|disable) will be called multiple times.
The above will happen when a panel drivers unconditionally
calls drm_panel_disable() in their shutdown() function,
whan the panel is already disabled and then shutdown() is called.
Reading the backlight code it seems safe to call
the backlight_(enable|disable) several times.
v3:
- Improve comments, fix grammar (Laurent)
- Do not fail in drm_panel_of_backlight() if no DT support (Laurent)
- Log if backlight_(enable|disable) fails (Laurent)
- Improve drm_panel_of_backlight() docs
- Updated changelog with backlight analysis (triggered by Laurent)
v2:
- Drop test of CONFIG_DRM_PANEL in header-file (Laurent)
- do not enable backlight if ->enable() returns an error
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20191207140353.23967-3-sam@ravnborg.org
Currently PREEMPT_RCU and TREE_RCU are mutually exclusive Kconfig
options. But PREEMPT_RCU actually specifies a kind of TREE_RCU,
namely a preemptible TREE_RCU. This commit therefore makes PREEMPT_RCU
be a modifer to the TREE_RCU Kconfig option. This has the benefit of
simplifying several of the #if expressions that formerly needed to
check both, but now need only check one or the other.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
We would like to use hlist_unhashed() from timer_pending(),
which runs without protection of a lock.
Note that other callers might also want to use this variant.
Instead of forcing a READ_ONCE() for all hlist_unhashed()
callers, add a new helper with an explicit _lockless suffix
in the name to better document what is going on.
Also add various WRITE_ONCE() in __hlist_del(), hlist_add_head()
and hlist_add_before()/hlist_add_behind() to pair with
the READ_ONCE().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
[ paulmck: Also add WRITE_ONCE() to rculist.h. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Without this patch, Sphinx shows "variable arguments" as the description
of the cond argument, rather than the intended description, and prints
the following warnings:
./include/linux/rculist.h:374: warning: Excess function parameter 'cond' description in 'list_for_each_entry_rcu'
./include/linux/rculist.h:651: warning: Excess function parameter 'cond' description in 'hlist_for_each_entry_rcu'
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
An expedited grace period can be stalled by a nohz_full CPU looping
in kernel context. This possibility is currently handled by some
carefully crafted checks in rcu_read_unlock_special() that enlist help
from ksoftirqd when permitted by the scheduler. However, it is exactly
these checks that require the scheduler avoid holding any of its rq or
pi locks across rcu_read_unlock() without also having held them across
the entire RCU read-side critical section.
It would therefore be very nice if expedited grace periods could
handle nohz_full CPUs looping in kernel context without such checks.
This commit therefore adds code to the expedited grace period's wait
and cleanup code that forces the scheduler-clock interrupt on for CPUs
that fail to quickly supply a quiescent state. "Quickly" is currently
a hard-coded single-jiffy delay.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This fixes a data-race where `atomic_t dynticks` is copied by value. The
copy is performed non-atomically, resulting in a data-race if `dynticks`
is updated concurrently.
This data-race was found with KCSAN:
==================================================================
BUG: KCSAN: data-race in dyntick_save_progress_counter / rcu_irq_enter
write to 0xffff989dbdbe98e0 of 4 bytes by task 10 on cpu 3:
atomic_add_return include/asm-generic/atomic-instrumented.h:78 [inline]
rcu_dynticks_snap kernel/rcu/tree.c:310 [inline]
dyntick_save_progress_counter+0x43/0x1b0 kernel/rcu/tree.c:984
force_qs_rnp+0x183/0x200 kernel/rcu/tree.c:2286
rcu_gp_fqs kernel/rcu/tree.c:1601 [inline]
rcu_gp_fqs_loop+0x71/0x880 kernel/rcu/tree.c:1653
rcu_gp_kthread+0x22c/0x3b0 kernel/rcu/tree.c:1799
kthread+0x1b5/0x200 kernel/kthread.c:255
<snip>
read to 0xffff989dbdbe98e0 of 4 bytes by task 154 on cpu 7:
rcu_nmi_enter_common kernel/rcu/tree.c:828 [inline]
rcu_irq_enter+0xda/0x240 kernel/rcu/tree.c:870
irq_enter+0x5/0x50 kernel/softirq.c:347
<snip>
Reported by Kernel Concurrency Sanitizer on:
CPU: 7 PID: 154 Comm: kworker/7:1H Not tainted 5.3.0+ #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Workqueue: kblockd blk_mq_run_work_fn
==================================================================
Signed-off-by: Marco Elver <elver@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
When building this on a 64-bit platform gcc rightly warns that the
error checking is broken (-ENOMEM stored in an u32 does not compare
greater than (unsigned long)-MAX_ERRNO). Instead, change the
ucc_fast_[tr]x_virtual_fifo_base_offset members to s32 and use an
ordinary check-for-negative. Also, this avoids treating 0 as "this
cannot have been returned from qe_muram_alloc() so don't free it".
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
When trying to build this for a 64-bit platform, one gets warnings
from using IS_ERR_VALUE on something which is not sizeof(long).
Instead, change the various *_offset fields to store a signed integer,
and simply check for a negative return from qe_muram_alloc(). Since
qe_muram_free() now accepts and ignores a negative argument, we only
need to make sure these fields are initialized with -1, and we can
just unconditionally call qe_muram_free() in ucc_slow_free().
Note that the error case for us_pram_offset failed to set that field
to 0 (which, as noted earlier, is anyway a bogus sentinel value).
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
Nobody uses the return value from cpm_muram_free, and functions that
free resources usually return void. One could imagine a use for a "how
much have I allocated" a la ksize(), but knowing how much one had
access to after the fact is useless.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
There are a number of problems with cpm_muram_alloc() and its
callers. Most callers assign the return value to some variable and
then use IS_ERR_VALUE to check for allocation failure. However, when
that variable is not sizeof(long), this leads to warnings - and it is
indeed broken to do e.g.
u32 foo = cpm_muram_alloc();
if (IS_ERR_VALUE(foo))
on a 64-bit platform, since the condition
foo >= (unsigned long)-ENOMEM
is tautologically false. There are also callers that ignore the
possibility of error, and then there are those that check for error by
comparing the return value to 0...
One could fix that by changing all callers to store the return value
temporarily in an "unsigned long" and test that. However, use of
IS_ERR_VALUE() is error-prone and should be restricted to things which
are inherently long-sized (stuff in pt_regs etc.). Instead, let's aim
for changing to the standard kernel style
int foo = cpm_muram_alloc();
if (foo < 0)
deal_with_it()
some->where = foo;
Changing the return type from unsigned long to s32 (aka signed int)
doesn't change the value that gets stored into any of the callers'
variables except if the caller was storing the result in a u64 _and_
the allocation failed, so in itself this patch should be a no-op.
Another problem with cpm_muram_alloc() is that it can certainly
validly return 0 - and except if some cpm_muram_alloc_fixed() call
interferes, the very first cpm_muram_alloc() call will return just
that. But that shows that both ucc_slow_free() and ucc_fast_free() are
buggy, since they assume that a value of 0 means "that field was never
allocated". We'll later change cpm_muram_free() to accept (and ignore)
a negative offset, so callers can use a sentinel of -1 instead of 0
and just unconditionally call cpm_muram_free().
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
asm/cpm.h under arch/powerpc is now just a wrapper for including
soc/fsl/cpm.h. In order to make the qe.h header usable on other
architectures, use the latter path directly.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
Some drivers, e.g. ucc_uart, need definitions from cpm.h. In order to
allow building those drivers for non-ppc based SOCs, move the header
to include/soc/fsl. For now, leave a trivial wrapper at the old
location so drivers can be updated one by one.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
The public qe_ic.h header is no longer included by anything but
qe_ic.c. Merge both headers into qe_ic.c, and drop the unused
constants.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
There are no current callers of these functions, and they use the
ppc-specific virq_to_hw(). So removing them gets us one step closer to
building QE support for ARM.
If the functionality is ever actually needed, the code can be dug out
of git and then adapted to work on all architectures, but for future
reference please note that I believe qe_ic_set_priority is buggy: The
"priority < 4" should be "priority <= 4", and in the else branch 24
should be replaced by 28, at least if I'm reading the data sheet right.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
These functions are only ever called through a function pointer, and
therefore it makes no sense for them to be "static inline" - gcc has
no choice but to emit a copy in each translation unit that takes the
address of one of these. Since they are now only referenced from
qe_ic.c, just make them local to that file.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
Having to call qe_ic_init() from platform-specific code makes it
awkward to allow building the QE drivers for ARM. It's also a needless
duplication of code, and slightly error-prone: Instead of the caller
needing to know the details of whether the QUICC Engine High and QUICC
Engine Low are actually the same interrupt (see e.g. the machine_is()
in mpc85xx_mds_qeic_init), just let the init function choose the
appropriate handlers after it has parsed the DT and figured it out. If
the two interrupts are distinct, use separate handlers, otherwise use
the handler which first checks the CHIVEC register (for the high
priority interrupts), then the CIVEC.
All existing callers pass 0 for flags, so continue to do that from the
new single caller. Later cleanups will remove that argument
from qe_ic_init and simplify the body, as well as make qe_ic_init into
a proper init function for an IRQCHIP_DECLARE, eliminating the need to
manually look up the fsl,qe-ic node.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
The *_ipic and *_mpic handlers are almost identical - the only
difference is that the latter end with an unconditional
chip->irq_eoi() call. Since IPIC does not have ->irq_eoi, we can
reduce some code duplication by calling irq_eoi conditionally.
This is similar to what is already done in mpc8xxx_gpio_irq_cascade().
This leaves the functions slightly misnamed, but that will be fixed in
a subsequent patch.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
The QUICC engine drivers use the powerpc-specific out_be32() etc. In
order to allow those drivers to build for other architectures, those
must be replaced by iowrite32be(). However, on powerpc, out_be32() is
a simple inline function while iowrite32be() is out-of-line. So in
order not to introduce a performance regression on powerpc when making
the drivers work on other architectures, introduce qe_io* helpers.
Also define the qe_{clr,set,clrset}bits* helpers in terms of these new
macros.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
Make it clear that these operate on big-endian registers (i.e. use the
iowrite*be primitives) before we introduce more uses of them and allow
the QE drivers to be built for platforms other than ppc32.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
Pull pr_warning() removal from Petr Mladek.
- Final removal of the unused pr_warning() alias.
You're supposed to use just "pr_warn()" in the kernel.
* tag 'printk-for-5.5-pr-warning-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
checkpatch: Drop pr_warning check
printk: Drop pr_warning definition
Fix up for "printk: Drop pr_warning definition"
workqueue: Use pr_warn instead of pr_warning
Currently the FW filename is obtained from the ACPI matching
table when determining which machine driver to use. In
preparation for making the machine driver ACPI match optional
for Device Tree platforms and moving the machine driver selection
out of the SOF core, this patch introduces the default_fw_filename
member in struct sof_dev_desc.
Once the machine driver selection is moved out of SOF core,
the nocodec_fw_filename will become obsolete and will be removed.
Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20191204211556.12671-8-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except
at places where these are defined. Later patches will remove the unused
definition of FIELD_SIZEOF().
This patch is generated using following script:
EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h"
git grep -l -e "\bFIELD_SIZEOF\b" | while read file;
do
if [[ "$file" =~ $EXCLUDE_FILES ]]; then
continue
fi
sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file;
done
Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: David Miller <davem@davemloft.net> # for net
This is needed, because if the flag X25_ACCPT_APPRV_FLAG is not set on a
socket (manual call confirmation) and the channel is cleared by remote
before the manual call confirmation was sent, this situation needs to
be handled.
Signed-off-by: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
neigh_cleanup() has not been used for seven years, and was a wrong design.
Messing with shared pointer in bond_neigh_init() without proper
memory barriers would at least trigger syzbot complains eventually.
It is time to remove this stuff.
Fixes: b63b70d877 ("IPoIB: Use a private hash table for path lookup in xmit path")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With 'bytes(__u32)' being 32, a left-shift of 31 may happen which is
undefined for the signed 32-bit value 1. Avoid this by declaring 1 as
unsigned.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Document missing @arg in xxx_param_cb().
Describe all parameters of module_param_[named_]unsafe() and all
*_param_cb() to make ./scripts/kernel-doc happy.
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
We are about to replace the single-linked bridge list by a double-linked
one based on list.h, leading to the suppression of the encoder->bridge
field. But before we can do that we must provide a
drm_bridge_chain_get_first_bridge() bridge helper and patch all drivers
and core helpers to use it instead of directly accessing encoder->bridge.
Note that we still have 2 drivers (VC4 and Exynos) manipulating the
encoder->bridge field directly because they need to cut the bridge chain
in order to control the enable/disable sequence. This is definitely
not something we want to encourage, so let's keep those 2 oddities
around until we find a better solution.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203141515.3597631-4-boris.brezillon@collabora.com
