lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

drm/i915/ringbuffer: set FORCE_WAKE bit before reading ring register

Browse Source 
Before reading ring register, set FORCE_WAKE bit to prevent GT core
power down to low power state, otherwise we may read stale values.

Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
[ickle: added a udelay which seemed to do the trick on my SNB]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
This commit is contained in:
Zou Nan hai
2010-11-09 17:17:32 +08:00
committed by Chris Wilson
parent 527f9e907c
commit cae5852dca
4 changed files with 106 additions and 86 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/gpu/drm/i915/intel_ringbuffer.c
View File

@@ -708,7 +708,7 @@ static int intel_wrap_ring_buffer(struct intel_ring_buffer *ring)
int intel_wait_ring_buffer(struct intel_ring_buffer *ring, int n)
{
struct drm_device *dev = ring->dev;
drm_i915_private_t *dev_priv = dev->dev_private;
struct drm_i915_private *dev_priv = dev->dev_private;
unsigned long end;
u32 head;