[PATCH] drm: Add locking to resume_force_mode to prevent multiple
On Thu, Mar 22, 2012 at 6:57 PM, Chris Wilson wrote: > On Thu, 22 Mar 2012 18:25:55 -0400, Sean Paul > wrote: >> Add a mutex to protect resume_force_mode from being called multiple >> times. This fixes a bug observed on SNB where two wake sources call >> resume_force_mode and the FDI training fails as a result. The user >> facing result of this is complete screen corruption. > > Looks like a bug in i915_drv.c for calling that function without holding > the mode_config.lock Good catch, thanks for the feedback Chris. I'll submit a new patch to intel-gfx, please drop this one. Sean > -Chris > > -- > Chris Wilson, Intel Open Source Technology Centre
Re: [PATCH] drm: Add locking to resume_force_mode to prevent multiple
On Thu, Mar 22, 2012 at 6:57 PM, Chris Wilson ch...@chris-wilson.co.uk wrote: On Thu, 22 Mar 2012 18:25:55 -0400, Sean Paul seanp...@chromium.org wrote: Add a mutex to protect resume_force_mode from being called multiple times. This fixes a bug observed on SNB where two wake sources call resume_force_mode and the FDI training fails as a result. The user facing result of this is complete screen corruption. Looks like a bug in i915_drv.c for calling that function without holding the mode_config.lock Good catch, thanks for the feedback Chris. I'll submit a new patch to intel-gfx, please drop this one. Sean -Chris -- Chris Wilson, Intel Open Source Technology Centre ___ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel
[PATCH] drm: Add locking to resume_force_mode to prevent multiple
On Thu, 22 Mar 2012 18:25:55 -0400, Sean Paul wrote: > Add a mutex to protect resume_force_mode from being called multiple > times. This fixes a bug observed on SNB where two wake sources call > resume_force_mode and the FDI training fails as a result. The user > facing result of this is complete screen corruption. Looks like a bug in i915_drv.c for calling that function without holding the mode_config.lock -Chris -- Chris Wilson, Intel Open Source Technology Centre
[PATCH] drm: Add locking to resume_force_mode to prevent multiple
Add a mutex to protect resume_force_mode from being called multiple
times. This fixes a bug observed on SNB where two wake sources call
resume_force_mode and the FDI training fails as a result. The user
facing result of this is complete screen corruption.
Signed-off-by: Sean Paul
---
drivers/gpu/drm/drm_crtc_helper.c |8
drivers/gpu/drm/drm_stub.c|1 +
include/drm/drmP.h|1 +
3 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/gpu/drm/drm_crtc_helper.c
b/drivers/gpu/drm/drm_crtc_helper.c
index 8111889..de7e492 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -882,6 +882,13 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
struct drm_crtc_helper_funcs *crtc_funcs;
int ret;
+ /* Make sure we're not already resuming, this can really screw
+* things up! */
+ if (mutex_trylock(>resume_mutex) == 0) {
+ DRM_DEBUG("Already in resume_force_mode\n");
+ return 0;
+ }
+
list_for_each_entry(crtc, >mode_config.crtc_list, head) {
if (!crtc->enabled)
@@ -914,6 +921,7 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
}
/* disable the unused connectors while restoring the modesetting */
drm_helper_disable_unused_functions(dev);
+ mutex_unlock(>resume_mutex);
return 0;
}
EXPORT_SYMBOL(drm_helper_resume_force_mode);
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index aa454f8..f35bed5 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -273,6 +273,7 @@ int drm_fill_in_dev(struct drm_device *dev,
spin_lock_init(>count_lock);
spin_lock_init(>event_lock);
mutex_init(>struct_mutex);
+ mutex_init(>resume_mutex);
mutex_init(>ctxlist_mutex);
if (drm_ht_create(>map_hash, 12)) {
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 574bd1c..75395a8 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1034,6 +1034,7 @@ struct drm_device {
/*@{ */
spinlock_t count_lock; /**< For inuse, drm_device::open_count,
drm_device::buf_use */
struct mutex struct_mutex; /**< For others */
+ struct mutex resume_mutex; /**< For drm_helper_resume_force_mode */
/*@} */
/** \name Usage Counters */
--
1.7.7.3
[PATCH] drm: Add locking to resume_force_mode to prevent multiple
Add a mutex to protect resume_force_mode from being called multiple
times. This fixes a bug observed on SNB where two wake sources call
resume_force_mode and the FDI training fails as a result. The user
facing result of this is complete screen corruption.
Signed-off-by: Sean Paul seanp...@chromium.org
---
drivers/gpu/drm/drm_crtc_helper.c |8
drivers/gpu/drm/drm_stub.c|1 +
include/drm/drmP.h|1 +
3 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/gpu/drm/drm_crtc_helper.c
b/drivers/gpu/drm/drm_crtc_helper.c
index 8111889..de7e492 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -882,6 +882,13 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
struct drm_crtc_helper_funcs *crtc_funcs;
int ret;
+ /* Make sure we're not already resuming, this can really screw
+* things up! */
+ if (mutex_trylock(dev-resume_mutex) == 0) {
+ DRM_DEBUG(Already in resume_force_mode\n);
+ return 0;
+ }
+
list_for_each_entry(crtc, dev-mode_config.crtc_list, head) {
if (!crtc-enabled)
@@ -914,6 +921,7 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
}
/* disable the unused connectors while restoring the modesetting */
drm_helper_disable_unused_functions(dev);
+ mutex_unlock(dev-resume_mutex);
return 0;
}
EXPORT_SYMBOL(drm_helper_resume_force_mode);
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index aa454f8..f35bed5 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -273,6 +273,7 @@ int drm_fill_in_dev(struct drm_device *dev,
spin_lock_init(dev-count_lock);
spin_lock_init(dev-event_lock);
mutex_init(dev-struct_mutex);
+ mutex_init(dev-resume_mutex);
mutex_init(dev-ctxlist_mutex);
if (drm_ht_create(dev-map_hash, 12)) {
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 574bd1c..75395a8 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1034,6 +1034,7 @@ struct drm_device {
/*@{ */
spinlock_t count_lock; /** For inuse, drm_device::open_count,
drm_device::buf_use */
struct mutex struct_mutex; /** For others */
+ struct mutex resume_mutex; /** For drm_helper_resume_force_mode */
/*@} */
/** \name Usage Counters */
--
1.7.7.3
___
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Re: [PATCH] drm: Add locking to resume_force_mode to prevent multiple
On Thu, 22 Mar 2012 18:25:55 -0400, Sean Paul seanp...@chromium.org wrote: Add a mutex to protect resume_force_mode from being called multiple times. This fixes a bug observed on SNB where two wake sources call resume_force_mode and the FDI training fails as a result. The user facing result of this is complete screen corruption. Looks like a bug in i915_drv.c for calling that function without holding the mode_config.lock -Chris -- Chris Wilson, Intel Open Source Technology Centre ___ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel
