diff options
| author | Dave Airlie | 2010-07-20 13:15:31 +1000 |
|---|---|---|
| committer | Dave Airlie | 2010-07-20 15:24:18 +1000 |
| commit | 944001201ca0196bcdb088129e5866a9f379d08c (patch) | |
| tree | eb8b2b2a9b00f469c283c5714c6d642db8aaa46b | |
| parent | 45503ded966c98e604c9667c0b458d40666b9ef3 (diff) | |
drm/i915: enable low power render writes on GEN3 hardware.
A lot of 945GMs have had stability issues for a long time, this manifested as X hangs, blitter engine hangs, and lots of crashes.
one such report is at:
https://bugs.freedesktop.org/show_bug.cgi?id=20560
along with numerous distro bugzillas.
This only took a week of digging and hair ripping to figure out.
Tracked down and tested on a 945GM Lenovo T60,
previously running
x11perf -copypixwin500
or
x11perf -copywinpix500
repeatedly would cause the GPU to wedge within 4 or 5 tries, with random busy bits set.
After this patch no hangs were observed.
cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 074385882ccf..43ce3809ef64 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -4741,6 +4741,16 @@ i915_gem_load(struct drm_device *dev) list_add(&dev_priv->mm.shrink_list, &shrink_list); spin_unlock(&shrink_list_lock); + /* On GEN3 we really need to make sure the ARB C3 LP bit is set */ + if (IS_GEN3(dev)) { + u32 tmp = I915_READ(MI_ARB_STATE); + if (!(tmp & MI_ARB_C3_LP_WRITE_ENABLE)) { + /* arb state is a masked write, so set bit + bit in mask */ + tmp = MI_ARB_C3_LP_WRITE_ENABLE | (MI_ARB_C3_LP_WRITE_ENABLE << MI_ARB_MASK_SHIFT); + I915_WRITE(MI_ARB_STATE, tmp); + } + } + /* Old X drivers will take 0-2 for front, back, depth buffers */ if (!drm_core_check_feature(dev, DRIVER_MODESET)) dev_priv->fence_reg_start = 3; |