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| author | Ben Widawsky <ben@bwidawsk.net> | 2012-09-02 09:59:50 +0400 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-09-03 12:28:32 +0400 |
| commit | 8dee3eea3ccd3b6c00a8d3a08dd715d6adf737dd (patch) | |
| tree | 8a31d9d71d99ad8bf73267aac1b833108122c4f8 /drivers/gpu/drm/i915/intel_pm.c | |
| parent | 057d3860613813b2e8507bb932f9a523ad2cca2f (diff) | |
| download | linux-8dee3eea3ccd3b6c00a8d3a08dd715d6adf737dd.tar.xz | |
drm/i915: Never read FORCEWAKE
The same designer from the previous patch has told us to never read
FORCEWAKE. We only do this for the POSTING_READ(), so simply change that
to something within the same cacheline (for no reason in particular
other than it sounds nice). In the _mt case we can leverage
the gtfifodbg check for the POSTING_READ.
This partially reverts
commit 6af2d180f82151cf3d58952e35a4f96e45bc453a
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Thu Jul 26 16:24:50 2012 +0200
drm/i915: fix forcewake related hangs on snb
v2: commit message, comments about posting read from (Daniel)
Note: vlv forcewake doesn't need any changes for this special
treatment since FORCEWAKE_VLV is in a totally different register
range, and the readback FORCEWAKE_ACK_VLV readback that follows is in
the same range.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Added note.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_pm.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_pm.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 31e47387ab9c..36c64091bc90 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -3969,7 +3969,7 @@ static void __gen6_gt_force_wake_get(struct drm_i915_private *dev_priv) DRM_ERROR("Timed out waiting for forcewake old ack to clear.\n"); I915_WRITE_NOTRACE(FORCEWAKE, 1); - POSTING_READ(FORCEWAKE); + POSTING_READ(ECOBUS); /* something from same cacheline, but !FORCEWAKE */ if (wait_for_atomic((I915_READ_NOTRACE(forcewake_ack) & 1), FORCEWAKE_ACK_TIMEOUT_MS)) @@ -3992,7 +3992,7 @@ static void __gen6_gt_force_wake_mt_get(struct drm_i915_private *dev_priv) DRM_ERROR("Timed out waiting for forcewake old ack to clear.\n"); I915_WRITE_NOTRACE(FORCEWAKE_MT, _MASKED_BIT_ENABLE(1)); - POSTING_READ(FORCEWAKE_MT); + POSTING_READ(ECOBUS); /* something from same cacheline, but !FORCEWAKE */ if (wait_for_atomic((I915_READ_NOTRACE(forcewake_ack) & 1), FORCEWAKE_ACK_TIMEOUT_MS)) @@ -4029,14 +4029,14 @@ void gen6_gt_check_fifodbg(struct drm_i915_private *dev_priv) static void __gen6_gt_force_wake_put(struct drm_i915_private *dev_priv) { I915_WRITE_NOTRACE(FORCEWAKE, 0); - POSTING_READ(FORCEWAKE); + /* gen6_gt_check_fifodbg doubles as the POSTING_READ */ gen6_gt_check_fifodbg(dev_priv); } static void __gen6_gt_force_wake_mt_put(struct drm_i915_private *dev_priv) { I915_WRITE_NOTRACE(FORCEWAKE_MT, _MASKED_BIT_DISABLE(1)); - POSTING_READ(FORCEWAKE_MT); + /* gen6_gt_check_fifodbg doubles as the POSTING_READ */ gen6_gt_check_fifodbg(dev_priv); } |