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Dmitry Baryshkov 15fe53be46
drm/bridge: lt9611uxc: fix the race in the error path
If DSI host attachment fails, the LT9611UXC driver will remove the
bridge without ensuring that there is no outstanding HPD work being
done. In rare cases this can result in the warnings regarding the mutex
being incorrect. Fix this by forcebly freing IRQ and flushing the work.

DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: CPU: 0 PID: 10 at kernel/locking/mutex.c:582 __mutex_lock+0x468/0x77c
Modules linked in:
CPU: 0 PID: 10 Comm: kworker/0:1 Tainted: G     U             6.6.0-rc5-next-20231011-gd81f81c2b682-dirty #1206
Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
Workqueue: events lt9611uxc_hpd_work
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __mutex_lock+0x468/0x77c
lr : __mutex_lock+0x468/0x77c
sp : ffff8000800a3c70
x29: ffff8000800a3c70 x28: 0000000000000000 x27: ffffd595fe333000
x26: ffff7c2f0002c005 x25: ffffd595ff1b3000 x24: ffffd595fccda5a0
x23: 0000000000000000 x22: 0000000000000002 x21: ffff7c2f056d91c8
x20: 0000000000000000 x19: ffff7c2f056d91c8 x18: fffffffffffe8db0
x17: 000000040044ffff x16: 005000f2b5503510 x15: 0000000000000000
x14: 000000000006efb8 x13: 0000000000000000 x12: 0000000000000037
x11: 0000000000000001 x10: 0000000000001470 x9 : ffff8000800a3ae0
x8 : ffff7c2f0027f8d0 x7 : ffff7c2f0027e400 x6 : ffffd595fc702b54
x5 : 0000000000000000 x4 : ffff8000800a0000 x3 : 0000000000000000
x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff7c2f0027e400
Call trace:
 __mutex_lock+0x468/0x77c
 mutex_lock_nested+0x24/0x30
 drm_bridge_hpd_notify+0x2c/0x5c
 lt9611uxc_hpd_work+0x6c/0x80
 process_one_work+0x1ec/0x51c
 worker_thread+0x1ec/0x3e4
 kthread+0x120/0x124
 ret_from_fork+0x10/0x20
irq event stamp: 15799
hardirqs last  enabled at (15799): [<ffffd595fc702ba4>] finish_task_switch.isra.0+0xa8/0x278
hardirqs last disabled at (15798): [<ffffd595fd5a1580>] __schedule+0x7b8/0xbd8
softirqs last  enabled at (15794): [<ffffd595fc690698>] __do_softirq+0x498/0x4e0
softirqs last disabled at (15771): [<ffffd595fc69615c>] ____do_softirq+0x10/0x1c

Fixes: bc6fa8676e ("drm/bridge/lontium-lt9611uxc: move HPD notification out of IRQ handler")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231011220002.382422-1-dmitry.baryshkov@linaro.org
2023-10-16 11:44:27 +02:00
arch fbdev: Replace fb_pgprotect() with pgprot_framebuffer() 2023-10-12 09:20:46 +02:00
block blk-mq: fix tags UAF when shrinking q->nr_hw_queues 2023-09-11 16:17:34 -06:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto This update includes the following changes: 2023-08-29 11:23:29 -07:00
Documentation dt-bindings: display: bridge: Document Freescale i.MX93 MIPI DSI 2023-10-16 11:38:46 +02:00
drivers drm/bridge: lt9611uxc: fix the race in the error path 2023-10-16 11:44:27 +02:00
fs stat: remove no-longer-used helper macros 2023-09-17 10:46:12 -07:00
include drm/bridge: synopsys: dw-mipi-dsi: Add mode fixup support 2023-10-16 11:38:42 +02:00
init workqueue: Changes for v6.6 2023-09-01 16:06:32 -07:00
io_uring io_uring/net: fix iter retargeting for selected buf 2023-09-14 10:12:55 -06:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel Fix a performance regression on large SMT systems, an Intel SMT4 2023-09-17 11:10:23 -07:00
lib linux-kselftest-kunit-6.6-rc2 2023-09-12 09:05:49 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm vm: fix move_vma() memory accounting being off 2023-09-16 15:23:31 -07:00
net kcm: Fix error handling for SOCK_DGRAM in kcm_sendmsg(). 2023-09-14 10:43:51 +02:00
rust Documentation work keeps chugging along; stuff for 6.6 includes: 2023-08-30 20:05:42 -07:00
samples VFIO updates for v6.6-rc1 2023-08-30 20:36:01 -07:00
scripts Kbuild fixes for v6.6 2023-09-16 15:27:00 -07:00
security selinux: fix handling of empty opts in selinux_fs_context_submount() 2023-09-12 17:31:08 -04:00
sound sound fixes for 6.6-rc1 2023-09-08 13:07:50 -07:00
tools Fix a cold functions related false-positive objtool warning 2023-09-17 10:59:37 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap for-linus-2023083101 2023-09-01 12:31:44 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: Update entry for megachips-stdpxxxx-ge-b850v3-fw 2023-10-13 16:29:13 +02:00
Makefile Linux 6.6-rc2 2023-09-17 14:40:24 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.