The linux-next integration testing tree
Go to file
baozhu.liu 19ecbe8325 drm/komeda: drop all currently held locks if deadlock happens
If komeda_pipeline_unbound_components() returns -EDEADLK,
it means that a deadlock happened in the locking context.
Currently, komeda is not dealing with the deadlock properly,producing the
following output when CONFIG_DEBUG_WW_MUTEX_SLOWPATH is enabled:

 ------------[ cut here ]------------
[   26.103984] WARNING: CPU: 2 PID: 345 at drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c:1248
	       komeda_release_unclaimed_resources+0x13c/0x170
[   26.117453] Modules linked in:
[   26.120511] CPU: 2 PID: 345 Comm: composer@2.1-se Kdump: loaded Tainted: G   W  5.10.110-SE-SDK1.8-dirty #16
[   26.131374] Hardware name: Siengine Se1000 Evaluation board (DT)
[   26.137379] pstate: 20400009 (nzCv daif +PAN -UAO -TCO BTYPE=--)
[   26.143385] pc : komeda_release_unclaimed_resources+0x13c/0x170
[   26.149301] lr : komeda_release_unclaimed_resources+0xbc/0x170
[   26.155130] sp : ffff800017b8b8d0
[   26.158442] pmr_save: 000000e0
[   26.161493] x29: ffff800017b8b8d0 x28: ffff000cf2f96200
[   26.166805] x27: ffff000c8f5a8800 x26: 0000000000000000
[   26.172116] x25: 0000000000000038 x24: ffff8000116a0140
[   26.177428] x23: 0000000000000038 x22: ffff000cf2f96200
[   26.182739] x21: ffff000cfc300300 x20: ffff000c8ab77080
[   26.188051] x19: 0000000000000003 x18: 0000000000000000
[   26.193362] x17: 0000000000000000 x16: 0000000000000000
[   26.198672] x15: b400e638f738ba38 x14: 0000000000000000
[   26.203983] x13: 0000000106400a00 x12: 0000000000000000
[   26.209294] x11: 0000000000000000 x10: 0000000000000000
[   26.214604] x9 : ffff800012f80000 x8 : ffff000ca3308000
[   26.219915] x7 : 0000000ff3000000 x6 : ffff80001084034c
[   26.225226] x5 : ffff800017b8bc40 x4 : 000000000000000f
[   26.230536] x3 : ffff000ca3308000 x2 : 0000000000000000
[   26.235847] x1 : 0000000000000000 x0 : ffffffffffffffdd
[   26.241158] Call trace:
[   26.243604] komeda_release_unclaimed_resources+0x13c/0x170
[   26.249175] komeda_crtc_atomic_check+0x68/0xf0
[   26.253706] drm_atomic_helper_check_planes+0x138/0x1f4
[   26.258929] komeda_kms_check+0x284/0x36c
[   26.262939] drm_atomic_check_only+0x40c/0x714
[   26.267381] drm_atomic_nonblocking_commit+0x1c/0x60
[   26.272344] drm_mode_atomic_ioctl+0xa3c/0xb8c
[   26.276787] drm_ioctl_kernel+0xc4/0x120
[   26.280708] drm_ioctl+0x268/0x534
[   26.284109] __arm64_sys_ioctl+0xa8/0xf0
[   26.288030] el0_svc_common.constprop.0+0x80/0x240
[   26.292817] do_el0_svc+0x24/0x90
[   26.296132] el0_svc+0x20/0x30
[   26.299185] el0_sync_handler+0xe8/0xf0
[   26.303018] el0_sync+0x1a4/0x1c0
[   26.306330] irq event stamp: 0
[   26.309384] hardirqs last  enabled at (0): [<0000000000000000>] 0x0
[   26.315650] hardirqs last disabled at (0): [<ffff800010056d34>] copy_process+0x5d0/0x183c
[   26.323825] softirqs last  enabled at (0): [<ffff800010056d34>] copy_process+0x5d0/0x183c
[   26.331997] softirqs last disabled at (0): [<0000000000000000>] 0x0
[   26.338261] ---[ end trace 20ae984fa860184a ]---
[   26.343021] ------------[ cut here ]------------
[   26.347646] WARNING: CPU: 3 PID: 345 at drivers/gpu/drm/drm_modeset_lock.c:228 drm_modeset_drop_locks+0x84/0x90
[   26.357727] Modules linked in:
[   26.360783] CPU: 3 PID: 345 Comm: composer@2.1-se Kdump: loaded Tainted: G   W  5.10.110-SE-SDK1.8-dirty #16
[   26.371645] Hardware name: Siengine Se1000 Evaluation board (DT)
[   26.377647] pstate: 20400009 (nzCv daif +PAN -UAO -TCO BTYPE=--)
[   26.383649] pc : drm_modeset_drop_locks+0x84/0x90
[   26.388351] lr : drm_mode_atomic_ioctl+0x860/0xb8c
[   26.393137] sp : ffff800017b8bb10
[   26.396447] pmr_save: 000000e0
[   26.399497] x29: ffff800017b8bb10 x28: 0000000000000001
[   26.404807] x27: 0000000000000038 x26: 0000000000000002
[   26.410115] x25: ffff000cecbefa00 x24: ffff000cf2f96200
[   26.415423] x23: 0000000000000001 x22: 0000000000000018
[   26.420731] x21: 0000000000000001 x20: ffff800017b8bc10
[   26.426039] x19: 0000000000000000 x18: 0000000000000000
[   26.431347] x17: 0000000002e8bf2c x16: 0000000002e94c6b
[   26.436655] x15: 0000000002ea48b9 x14: ffff8000121f0300
[   26.441963] x13: 0000000002ee2ca8 x12: ffff80001129cae0
[   26.447272] x11: ffff800012435000 x10: ffff000ed46b5e88
[   26.452580] x9 : ffff000c9935e600 x8 : 0000000000000000
[   26.457888] x7 : 000000008020001e x6 : 000000008020001f
[   26.463196] x5 : ffff80001085fbe0 x4 : fffffe0033a59f20
[   26.468504] x3 : 000000008020001e x2 : 0000000000000000
[   26.473813] x1 : 0000000000000000 x0 : ffff000c8f596090
[   26.479122] Call trace:
[   26.481566] drm_modeset_drop_locks+0x84/0x90
[   26.485918] drm_mode_atomic_ioctl+0x860/0xb8c
[   26.490359] drm_ioctl_kernel+0xc4/0x120
[   26.494278] drm_ioctl+0x268/0x534
[   26.497677] __arm64_sys_ioctl+0xa8/0xf0
[   26.501598] el0_svc_common.constprop.0+0x80/0x240
[   26.506384] do_el0_svc+0x24/0x90
[   26.509697] el0_svc+0x20/0x30
[   26.512748] el0_sync_handler+0xe8/0xf0
[   26.516580] el0_sync+0x1a4/0x1c0
[   26.519891] irq event stamp: 0
[   26.522943] hardirqs last  enabled at (0): [<0000000000000000>] 0x0
[   26.529207] hardirqs last disabled at (0): [<ffff800010056d34>] copy_process+0x5d0/0x183c
[   26.537379] softirqs last  enabled at (0): [<ffff800010056d34>] copy_process+0x5d0/0x183c
[   26.545550] softirqs last disabled at (0): [<0000000000000000>] 0x0
[   26.551812] ---[ end trace 20ae984fa860184b ]---

According to the call trace information,it can be located to be
WARN_ON(IS_ERR(c_st)) in the komeda_pipeline_unbound_components function;
Then follow the function.
komeda_pipeline_unbound_components
-> komeda_component_get_state_and_set_user
  -> komeda_pipeline_get_state_and_set_crtc
    -> komeda_pipeline_get_state
      ->drm_atomic_get_private_obj_state
        -> drm_atomic_get_private_obj_state
          -> drm_modeset_lock

komeda_pipeline_unbound_components
-> komeda_component_get_state_and_set_user
  -> komeda_component_get_state
    -> drm_atomic_get_private_obj_state
     -> drm_modeset_lock

ret = drm_modeset_lock(&obj->lock, state->acquire_ctx); if (ret)
	return ERR_PTR(ret);
Here it return -EDEADLK.

deal with the deadlock as suggested by [1], using the
function drm_modeset_backoff().
[1] https://docs.kernel.org/gpu/drm-kms.html?highlight=kms#kms-locking

Therefore, handling this problem can be solved
by adding return -EDEADLK back to the drm_modeset_backoff processing flow
in the drm_mode_atomic_ioctl function.

Signed-off-by: baozhu.liu <lucas.liu@siengine.com>
Signed-off-by: menghui.huang <menghui.huang@siengine.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230804013117.6870-1-menghui.huang@siengine.com
2023-08-31 16:38:04 +01:00
arch sh: mach-sh7763rdp: Assign FB_MODE_IS_UNKNOWN to struct fb_videomode.flag 2023-07-24 16:50:38 +02:00
block SCSI fixes on 20230714 2023-07-14 19:57:29 -07:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto crypto: algif_hash - Fix race between MORE and non-MORE sends 2023-07-08 22:48:42 +10:00
Documentation doc: uapi: Add document describing dma-buf semantics 2023-08-21 18:20:05 +02:00
drivers drm/komeda: drop all currently held locks if deadlock happens 2023-08-31 16:38:04 +01:00
fs Five smb3 client fixes 2023-07-16 12:49:05 -07:00
include drm/nouveau: uapi: don't pass NO_PREFETCH flag implicitly 2023-08-24 01:43:00 +02:00
init Kbuild updates for v6.5 2023-07-01 09:24:31 -07:00
io_uring io_uring-6.5-2023-07-14 2023-07-14 19:46:54 -07:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel - Remove a cgroup from under a polling process properly 2023-07-16 13:22:08 -07:00
lib iov_iter: Mark copy_iovec_from_user() noclone 2023-07-10 09:52:28 +02:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm: lock newly mapped VMA with corrected ordering 2023-07-08 16:44:11 -07:00
net A fix to prevent a potential buffer overrun in the messenger, marked 2023-07-14 09:05:15 -07:00
rust rust: error: impl Debug for Error with errname() integration 2023-06-13 01:24:42 +02:00
samples vfio-dev/mdpy-fb: Use fbdev I/O helpers 2023-08-04 15:54:39 +02:00
scripts kallsyms: strip LTO-only suffixes from promoted global functions 2023-07-12 15:39:34 -07:00
security + Bug Fixes 2023-07-07 09:55:31 -07:00
sound sound fixes for 6.5-rc1 2023-07-07 15:40:17 -07:00
tools - Mark copy_iovec_from_user() __noclone in order to prevent gcc from 2023-07-16 13:34:29 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM64: 2023-07-03 15:32:22 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.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 Revert ".gitignore: ignore *.cover and *.mbx" 2023-07-04 15:05:12 -07:00
.mailmap spi: Fixes for v6.5 2023-07-15 08:51:02 -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 - Address -Wmissing-prototype warnings 2023-06-26 16:43:54 -07:00
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 doc: uapi: Add document describing dma-buf semantics 2023-08-21 18:20:05 +02:00
Makefile Linux 6.5-rc2 2023-07-16 15:10:37 -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.