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Groups > linux.kernel > #1621613 > unrolled thread
| Started by | Jeffy Chen <jeffy.chen@rock-chips.com> |
|---|---|
| First post | 2017-04-11 23:00 +0200 |
| Last post | 2017-04-11 23:10 +0200 |
| Articles | 2 — 2 participants |
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[PATCH] drm: Fixup hang when unregistering drm dev with open_count 0 Jeffy Chen <jeffy.chen@rock-chips.com> - 2017-04-11 23:00 +0200
Re: [PATCH] drm: Fixup hang when unregistering drm dev with open_count 0 Sean Paul <seanpaul@chromium.org> - 2017-04-11 23:10 +0200
| From | Jeffy Chen <jeffy.chen@rock-chips.com> |
|---|---|
| Date | 2017-04-11 23:00 +0200 |
| Subject | [PATCH] drm: Fixup hang when unregistering drm dev with open_count 0 |
| Message-ID | <tvb3k-3yo-17@gated-at.bofh.it> |
My previous patch (c5d8fac2bf drm: Unplug drm device when unregistering
it) calls drm_unplug_dev when unregistering drm dev. But if open_count
is 0, the unplug will try to unregister the drm dev again and cause
deadlock.
Fix it by dropping drm_unplug_dev and use drm_device_set_plug_state
directly.
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
---
drivers/gpu/drm/drm_drv.c | 15 +--------------
include/drm/drm_drv.h | 1 -
2 files changed, 1 insertion(+), 15 deletions(-)
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index ad13e20..cc2d018 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -355,19 +355,6 @@ void drm_put_dev(struct drm_device *dev)
}
EXPORT_SYMBOL(drm_put_dev);
-void drm_unplug_dev(struct drm_device *dev)
-{
- mutex_lock(&drm_global_mutex);
-
- drm_device_set_plug_state(dev, false);
-
- if (dev->open_count == 0) {
- drm_put_dev(dev);
- }
- mutex_unlock(&drm_global_mutex);
-}
-EXPORT_SYMBOL(drm_unplug_dev);
-
/*
* DRM internal mount
* We want to be able to allocate our own "struct address_space" to control
@@ -825,7 +812,7 @@ void drm_dev_unregister(struct drm_device *dev)
drm_lastclose(dev);
dev->registered = false;
- drm_unplug_dev(dev);
+ drm_device_set_plug_state(dev, false);
if (drm_core_check_feature(dev, DRIVER_MODESET))
drm_modeset_unregister_all(dev);
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index 0fefc3f..eb63078 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -544,7 +544,6 @@ void drm_dev_unregister(struct drm_device *dev);
void drm_dev_ref(struct drm_device *dev);
void drm_dev_unref(struct drm_device *dev);
void drm_put_dev(struct drm_device *dev);
-void drm_unplug_dev(struct drm_device *dev);
int drm_dev_set_unique(struct drm_device *dev, const char *name);
--
2.1.4
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| From | Sean Paul <seanpaul@chromium.org> |
|---|---|
| Date | 2017-04-11 23:10 +0200 |
| Subject | Re: [PATCH] drm: Fixup hang when unregistering drm dev with open_count 0 |
| Message-ID | <tvbd0-3RY-17@gated-at.bofh.it> |
| In reply to | #1621613 |
On Wed, Apr 12, 2017 at 04:57:54AM +0800, Jeffy Chen wrote:
> My previous patch (c5d8fac2bf drm: Unplug drm device when unregistering
> it) calls drm_unplug_dev when unregistering drm dev. But if open_count
> is 0, the unplug will try to unregister the drm dev again and cause
> deadlock.
>
> Fix it by dropping drm_unplug_dev and use drm_device_set_plug_state
> directly.
Hi Jeffy,
That patch was not applied anywhere, the test robot just picked it up from the
mailing list.
Please squash this into the original patch and re-send.
Thanks,
Sean
>
> Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
>
> ---
>
> drivers/gpu/drm/drm_drv.c | 15 +--------------
> include/drm/drm_drv.h | 1 -
> 2 files changed, 1 insertion(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index ad13e20..cc2d018 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -355,19 +355,6 @@ void drm_put_dev(struct drm_device *dev)
> }
> EXPORT_SYMBOL(drm_put_dev);
>
> -void drm_unplug_dev(struct drm_device *dev)
> -{
> - mutex_lock(&drm_global_mutex);
> -
> - drm_device_set_plug_state(dev, false);
> -
> - if (dev->open_count == 0) {
> - drm_put_dev(dev);
> - }
> - mutex_unlock(&drm_global_mutex);
> -}
> -EXPORT_SYMBOL(drm_unplug_dev);
> -
> /*
> * DRM internal mount
> * We want to be able to allocate our own "struct address_space" to control
> @@ -825,7 +812,7 @@ void drm_dev_unregister(struct drm_device *dev)
> drm_lastclose(dev);
>
> dev->registered = false;
> - drm_unplug_dev(dev);
> + drm_device_set_plug_state(dev, false);
>
> if (drm_core_check_feature(dev, DRIVER_MODESET))
> drm_modeset_unregister_all(dev);
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index 0fefc3f..eb63078 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -544,7 +544,6 @@ void drm_dev_unregister(struct drm_device *dev);
> void drm_dev_ref(struct drm_device *dev);
> void drm_dev_unref(struct drm_device *dev);
> void drm_put_dev(struct drm_device *dev);
> -void drm_unplug_dev(struct drm_device *dev);
>
> int drm_dev_set_unique(struct drm_device *dev, const char *name);
>
> --
> 2.1.4
>
--
Sean Paul, Software Engineer, Google / Chromium OS
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