| Message ID | 1450179356-22702-1-git-send-email-mika.kuoppala@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On ti, 2015-12-15 at 13:35 +0200, Mika Kuoppala wrote: > Some igt tests wants to drop caches by writing to this debugfs > entry. The call to shrinker may ensure and it wants to update > the fence registers, so hardware access happens. This access > can happen in a spot where the block containing these registers > might bepowered down. > > To avoid getting unclaimed register access trace noise due > to this, take a runtime pm reference during i915_drop_caches set. > > v2: pm_ref and mutex lock ordering (Chris) > > Cc: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> > Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com> > --- > drivers/gpu/drm/i915/i915_debugfs.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c > b/drivers/gpu/drm/i915/i915_debugfs.c > index 24318b7..d96709a 100644 > --- a/drivers/gpu/drm/i915/i915_debugfs.c > +++ b/drivers/gpu/drm/i915/i915_debugfs.c > @@ -4833,11 +4833,13 @@ i915_drop_caches_set(void *data, u64 val) > > DRM_DEBUG("Dropping caches: 0x%08llx\n", val); > > + intel_runtime_pm_get(dev_priv); > + > /* No need to check and wait for gpu resets, only libdrm > auto-restarts > * on ioctls on -EAGAIN. */ > ret = mutex_lock_interruptible(&dev->struct_mutex); > if (ret) > - return ret; > + goto pm_put; > > if (val & DROP_ACTIVE) { > ret = i915_gpu_idle(dev); > @@ -4856,7 +4858,9 @@ i915_drop_caches_set(void *data, u64 val) > > unlock: > mutex_unlock(&dev->struct_mutex); > - > +pm_put: > + intel_runtime_pm_put(dev_priv); > + > return ret; > } >
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 24318b7..d96709a 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -4833,11 +4833,13 @@ i915_drop_caches_set(void *data, u64 val) DRM_DEBUG("Dropping caches: 0x%08llx\n", val); + intel_runtime_pm_get(dev_priv); + /* No need to check and wait for gpu resets, only libdrm auto-restarts * on ioctls on -EAGAIN. */ ret = mutex_lock_interruptible(&dev->struct_mutex); if (ret) - return ret; + goto pm_put; if (val & DROP_ACTIVE) { ret = i915_gpu_idle(dev); @@ -4856,7 +4858,9 @@ i915_drop_caches_set(void *data, u64 val) unlock: mutex_unlock(&dev->struct_mutex); - +pm_put: + intel_runtime_pm_put(dev_priv); + return ret; }
Some igt tests wants to drop caches by writing to this debugfs entry. The call to shrinker may ensure and it wants to update the fence registers, so hardware access happens. This access can happen in a spot where the block containing these registers might bepowered down. To avoid getting unclaimed register access trace noise due to this, take a runtime pm reference during i915_drop_caches set. v2: pm_ref and mutex lock ordering (Chris) Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com> --- drivers/gpu/drm/i915/i915_debugfs.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)