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

2023-03-08 Thread Alex Deucher
On Wed, Mar 8, 2023 at 7:02 AM Mikhail Gavrilov
 wrote:
>
> 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 
> 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: 6005 (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 : 89ef3740
> x29: 89ef3740 x28: 09331f00 x27: 1000
> x26: 0020 x25: 81148ed8 x24: 0a8fe000
> x23: fffd x22: 05086348 x21: 81133ee0
> x20: 0550d800 x19: 05086288 x18: 0006
> x17:  x16: 896ef008 x15: 972891004260
> x14: 2a1403e19400 x13: 972891004260 x12: 2a1403e19400
> x11: 7100385f29400801 x10: 0aa0 x9 : 88112744
> x8 : 00250b00 x7 : 0003 x6 : 0011
> x5 :  x4 : bd986a48 x3 : 0001
> x2 :  x1 :  x0 : 0025
> 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  ]---
>
> Reported-by: Laurentiu Palcu 
> Fixes: c8268795c9a9 ("drm/probe-helper: enable and disable HPD on
> connectors")
> Tested-by: Marek Szyprowski 
> Tested-by: Chen-Yu Tsai 
> Acked-by: Laurentiu Palcu 
> Tested-by: Laurentiu Palcu 
> Tested-by: Laurent Pinchart 
> Signed-off-by: Dmitry Baryshkov 
> Signed-off-by: Neil Armstrong 
> Link: 
> https://patchwork.freedesktop.org/patch/msgid/20230124104548.3234554-2-dmitry.barysh...@linaro.org
> (cherry picked from commit d33a54e3991dfce88b4fc6d9c3360951c2c5660d)
> Signed-off-by: Thomas Zimmermann 
>
>  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 

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

2023-03-08 Thread 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 
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: 6005 (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 : 89ef3740
x29: 89ef3740 x28: 09331f00 x27: 1000
x26: 0020 x25: 81148ed8 x24: 0a8fe000
x23: fffd x22: 05086348 x21: 81133ee0
x20: 0550d800 x19: 05086288 x18: 0006
x17:  x16: 896ef008 x15: 972891004260
x14: 2a1403e19400 x13: 972891004260 x12: 2a1403e19400
x11: 7100385f29400801 x10: 0aa0 x9 : 88112744
x8 : 00250b00 x7 : 0003 x6 : 0011
x5 :  x4 : bd986a48 x3 : 0001
x2 :  x1 :  x0 : 0025
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  ]---

Reported-by: Laurentiu Palcu 
Fixes: c8268795c9a9 ("drm/probe-helper: enable and disable HPD on
connectors")
Tested-by: Marek Szyprowski 
Tested-by: Chen-Yu Tsai 
Acked-by: Laurentiu Palcu 
Tested-by: Laurentiu Palcu 
Tested-by: Laurent Pinchart 
Signed-off-by: Dmitry Baryshkov 
Signed-off-by: Neil Armstrong 
Link: 
https://patchwork.freedesktop.org/patch/msgid/20230124104548.3234554-2-dmitry.barysh...@linaro.org
(cherry picked from commit d33a54e3991dfce88b4fc6d9c3360951c2c5660d)
Signed-off-by: Thomas Zimmermann 

 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