[6.3][regression] commit a4e771729a51168bc36317effaa9962e336d4f5e lead to flood kernel logs with warning messages "at kernel/workqueue.c:3167 __flush_work+0x472/0x500"

[Mikhail Gavrilov]

Hi,
I didn't faced to issue drm_bridge_hpd_enable+0x94/0x9c [drm] but
fixing this issue leads to warning messages on my laptop ASUS ROG
Strix G15 Advantage Edition G513QY-HQ007 which has two AMD GPU.
Discrete Radeon 6800M and integrated in CPU Cezanne Vega 8.

I found bad commit by bisecting:
❯ git bisect bad
a4e771729a51168bc36317effaa9962e336d4f5e is the first bad commit
commit a4e771729a51168bc36317effaa9962e336d4f5e
Author: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Date:   Tue Jan 24 12:45:48 2023 +0200

    drm/probe_helper: sort out poll_running vs poll_enabled

    There are two flags attemting to guard connector polling:
    poll_enabled and poll_running. While poll_enabled semantics is clearly
    defined and fully adhered (mark that drm_kms_helper_poll_init() was
    called and not finalized by the _fini() call), the poll_running flag
    doesn't have such clearliness.

    This flag is used only in drm_helper_probe_single_connector_modes() to
    guard calling of drm_kms_helper_poll_enable, it doesn't guard the
    drm_kms_helper_poll_fini(), etc. Change it to only be set if the polling
    is actually running. Tie HPD enablement to this flag.

    This fixes the following warning reported after merging the HPD series:

    Hot plug detection already enabled
    WARNING: CPU: 2 PID: 9 at drivers/gpu/drm/drm_bridge.c:1257
drm_bridge_hpd_enable+0x94/0x9c [drm]
    Modules linked in: videobuf2_memops snd_soc_simple_card
snd_soc_simple_card_utils fsl_imx8_ddr_perf videobuf2_common
snd_soc_imx_spdif adv7511 etnaviv imx8m_ddrc imx_dcss mc cec nwl_dsi
gov
    CPU: 2 PID: 9 Comm: kworker/u8:0 Not tainted
6.2.0-rc2-15208-g25b283acd578 #6
    Hardware name: NXP i.MX8MQ EVK (DT)
    Workqueue: events_unbound deferred_probe_work_func
    pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
    pc : drm_bridge_hpd_enable+0x94/0x9c [drm]
    lr : drm_bridge_hpd_enable+0x94/0x9c [drm]
    sp : ffff800009ef3740
    x29: ffff800009ef3740 x28: ffff000009331f00 x27: 0000000000001000
    x26: 0000000000000020 x25: ffff800001148ed8 x24: ffff00000a8fe000
    x23: 00000000fffffffd x22: ffff000005086348 x21: ffff800001133ee0
    x20: ffff00000550d800 x19: ffff000005086288 x18: 0000000000000006
    x17: 0000000000000000 x16: ffff8000096ef008 x15: 97ffff2891004260
    x14: 2a1403e194000000 x13: 97ffff2891004260 x12: 2a1403e194000000
    x11: 7100385f29400801 x10: 0000000000000aa0 x9 : ffff800008112744
    x8 : ffff000000250b00 x7 : 0000000000000003 x6 : 0000000000000011
    x5 : 0000000000000000 x4 : ffff0000bd986a48 x3 : 0000000000000001
    x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000000250000
    Call trace:
     drm_bridge_hpd_enable+0x94/0x9c [drm]
     drm_bridge_connector_enable_hpd+0x2c/0x3c [drm_kms_helper]
     drm_kms_helper_poll_enable+0x94/0x10c [drm_kms_helper]
     drm_helper_probe_single_connector_modes+0x1a8/0x510 [drm_kms_helper]
     drm_client_modeset_probe+0x204/0x1190 [drm]
     __drm_fb_helper_initial_config_and_unlock+0x5c/0x4a4 [drm_kms_helper]
     drm_fb_helper_initial_config+0x54/0x6c [drm_kms_helper]
     drm_fbdev_client_hotplug+0xd0/0x140 [drm_kms_helper]
     drm_fbdev_generic_setup+0x90/0x154 [drm_kms_helper]
     dcss_kms_attach+0x1c8/0x254 [imx_dcss]
     dcss_drv_platform_probe+0x90/0xfc [imx_dcss]
     platform_probe+0x70/0xcc
     really_probe+0xc4/0x2e0
     __driver_probe_device+0x80/0xf0
     driver_probe_device+0xe0/0x164
     __device_attach_driver+0xc0/0x13c
     bus_for_each_drv+0x84/0xe0
     __device_attach+0xa4/0x1a0
     device_initial_probe+0x1c/0x30
     bus_probe_device+0xa4/0xb0
     deferred_probe_work_func+0x90/0xd0
     process_one_work+0x200/0x474
     worker_thread+0x74/0x43c
     kthread+0xfc/0x110
     ret_from_fork+0x10/0x20
    ---[ end trace 0000000000000000 ]---

    Reported-by: Laurentiu Palcu <laurentiu.palcu@xxxxxxxxxxx>
    Fixes: c8268795c9a9 ("drm/probe-helper: enable and disable HPD on
connectors")
    Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
    Tested-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>
    Acked-by: Laurentiu Palcu <laurentiu.palcu@xxxxxxxxxxx>
    Tested-by: Laurentiu Palcu <laurentiu.palcu@xxxxxxxxxxx>
    Tested-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
    Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
    Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
    Link: https://patchwork.freedesktop.org/patch/msgid/20230124104548.3234554-2-dmitry.baryshkov@xxxxxxxxxx
    (cherry picked from commit d33a54e3991dfce88b4fc6d9c3360951c2c5660d)
    Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>

 drivers/gpu/drm/drm_probe_helper.c | 42 +++++++++++++++++++-------------------
 1 file changed, 21 insertions(+), 21 deletions(-)

Of course I tried to check the bisect assumption by reverting this
commit. And I can confirm without commit
a4e771729a51168bc36317effaa9962e336d4f5e the warning messages do not
appear within a day.

I attached a full kernel log if someone would be interested to see it.

-- 
Best Regards,
Mike Gavrilov.
git bisect start
# status: waiting for both good and bad commits
# good: [5b7c4cabbb65f5c469464da6c5f614cbd7f730f2] Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
git bisect good 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2
# status: waiting for bad commit, 1 good commit known
# bad: [a5c95ca18a98d742d0a4a04063c32556b5b66378] Merge tag 'drm-next-2023-02-23' of git://anongit.freedesktop.org/drm/drm
git bisect bad a5c95ca18a98d742d0a4a04063c32556b5b66378
# bad: [13daf536191e8c484fa21de8fcac4767f7b66e80] Merge tag 'drm-misc-next-fixes-2023-02-21' of git://anongit.freedesktop.org/drm/drm-misc into drm-next
git bisect bad 13daf536191e8c484fa21de8fcac4767f7b66e80
# good: [b8f55f24bc82ed7064645cc7f6675430609314a5] Merge tag 'drm-misc-next-2023-01-19' of git://anongit.freedesktop.org/drm/drm-misc into drm-next
git bisect good b8f55f24bc82ed7064645cc7f6675430609314a5
# good: [155c6b16eec2eaaaf6c71abf2d5e71641770d7ba] Merge tag 'amd-drm-next-6.3-2023-01-27' of https://gitlab.freedesktop.org/agd5f/linux into drm-next
git bisect good 155c6b16eec2eaaaf6c71abf2d5e71641770d7ba
# good: [15a574485700eac3b8611770d69a809b09cc8529] Merge tag 'drm-intel-gt-next-2023-02-01' of git://anongit.freedesktop.org/drm/drm-intel into drm-next
git bisect good 15a574485700eac3b8611770d69a809b09cc8529
# good: [d2c40a2d750e53f871a732d1cc11b92239cd3405] drm/amd/display: Simplify bool conversion
git bisect good d2c40a2d750e53f871a732d1cc11b92239cd3405
# good: [80c6d6804f31451848a3956a70c2bcb1f07cfcb0] drm/amd/display: disable SubVP + DRR to prevent underflow
git bisect good 80c6d6804f31451848a3956a70c2bcb1f07cfcb0
# good: [14e591a1930c2790fe862af5b01ee3ca587f752f] drm/i915: Populate encoder->devdata for DSI on icl+
git bisect good 14e591a1930c2790fe862af5b01ee3ca587f752f
# bad: [38b2d8efd03d2e56431b611e3523f0158306451d] drm: panel-orientation-quirks: Add quirk for Lenovo IdeaPad Duet 3 10IGL5
git bisect bad 38b2d8efd03d2e56431b611e3523f0158306451d
# good: [91f43949662c9eb4a443203a188e806df8290bc9] drm/probe_helper: extract two helper functions
git bisect good 91f43949662c9eb4a443203a188e806df8290bc9
# bad: [326b1e792ff08b4d8ecb9605aec98e4e5feef56e] drm/i915/dp_mst: Add the MST topology state for modesetted CRTCs
git bisect bad 326b1e792ff08b4d8ecb9605aec98e4e5feef56e
# bad: [467fbc77f673ecc9dcf4e58ffc1fa426a22df7fd] dt-bindings: display: panel: visionox,vtdr6130: add missing reg property
git bisect bad 467fbc77f673ecc9dcf4e58ffc1fa426a22df7fd
# bad: [a4e771729a51168bc36317effaa9962e336d4f5e] drm/probe_helper: sort out poll_running vs poll_enabled
git bisect bad a4e771729a51168bc36317effaa9962e336d4f5e
# first bad commit: [a4e771729a51168bc36317effaa9962e336d4f5e] drm/probe_helper: sort out poll_running vs poll_enabled

Attachment: dmesg.tar.xz
Description: application/xz