Dear Alex,
on my old P4 based non-SMP router your patch (commit
32d12fc20e3c726ca858d0e5055fb596fce2f8bc in linux stable) crashes on
Linux 4.1.4 and above. I was only able to take a picture of the whole
trace https://ferdi.naasa.net/url/jplatte/IMG_3116.JPG
Reverting the patch resolves the issue.
This is my old graphics hardware:
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc.
[AMD/ATI] RV100 [Radeon 7000 / Radeon VE]
Just for the reference, here is the full patch:
commit 32d12fc20e3c726ca858d0e5055fb596fce2f8bc
Author: Alex Deucher <[email protected]>
Date: Fri May 15 11:48:52 2015 -0400
drm/radeon: take the mode_config mutex when dealing with hpds (v2)
commit 39fa10f7e21574a70cecf1fed0f9b36535aa68a0 upstream.
Since we are messing with state in the worker.
v2: drop the changes in the mst worker
Signed-off-by: Alex Deucher <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c
b/drivers/gpu/drm/radeon/radeon_irq_kms.c
index 7162c93..f682e53 100644
--- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
@@ -79,10 +79,12 @@ static void radeon_hotplug_work_func(struct
work_struct *work)
struct drm_mode_config *mode_config = &dev->mode_config;
struct drm_connector *connector;
+ mutex_lock(&mode_config->mutex);
if (mode_config->num_connector) {
list_for_each_entry(connector,
&mode_config->connector_list, head)
radeon_connector_hotplug(connector);
}
+ mutex_unlock(&mode_config->mutex);
/* Just fire off a uevent and let userspace tell us what to do */
drm_helper_hpd_irq_event(dev);
}
Is it possible that the mutex is not defined on non-SMP systems? Can you
help to resolve this regression?
Best regards,
Joerg
> -----Original Message-----
> From: Joerg Platte [mailto:[email protected]]
> Sent: Sunday, August 23, 2015 11:26 PM
> To: Deucher, Alexander; [email protected]
> Subject: drm/radeon: take the mode_config mutex when dealing with hpds
> (v2) crashes
>
> Dear Alex,
>
> on my old P4 based non-SMP router your patch (commit
> 32d12fc20e3c726ca858d0e5055fb596fce2f8bc in linux stable) crashes on
> Linux 4.1.4 and above. I was only able to take a picture of the whole
> trace https://ferdi.naasa.net/url/jplatte/IMG_3116.JPG
>
> Reverting the patch resolves the issue.
>
> This is my old graphics hardware:
> 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc.
> [AMD/ATI] RV100 [Radeon 7000 / Radeon VE]
>
> Just for the reference, here is the full patch:
> commit 32d12fc20e3c726ca858d0e5055fb596fce2f8bc
> Author: Alex Deucher <[email protected]>
> Date: Fri May 15 11:48:52 2015 -0400
>
> drm/radeon: take the mode_config mutex when dealing with hpds (v2)
>
> commit 39fa10f7e21574a70cecf1fed0f9b36535aa68a0 upstream.
>
> Since we are messing with state in the worker.
>
> v2: drop the changes in the mst worker
>
> Signed-off-by: Alex Deucher <[email protected]>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>
>
> diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c
> b/drivers/gpu/drm/radeon/radeon_irq_kms.c
> index 7162c93..f682e53 100644
> --- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
> +++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
> @@ -79,10 +79,12 @@ static void radeon_hotplug_work_func(struct
> work_struct *work)
> struct drm_mode_config *mode_config = &dev->mode_config;
> struct drm_connector *connector;
>
> + mutex_lock(&mode_config->mutex);
> if (mode_config->num_connector) {
> list_for_each_entry(connector,
> &mode_config->connector_list, head)
> radeon_connector_hotplug(connector);
> }
> + mutex_unlock(&mode_config->mutex);
> /* Just fire off a uevent and let userspace tell us what to do */
> drm_helper_hpd_irq_event(dev);
> }
>
> Is it possible that the mutex is not defined on non-SMP systems? Can you
> help to resolve this regression?
Fixed in:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=7f98ca454ad373fc1b76be804fa7138ff68c1d27
Alex
>
> Best regards,
> Joerg
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