drm/i915: write D_COMP using the mailbox
You can't write it using the MCHBAR mirror, the write will just get
dropped.
This should make us BSpec-compliant, but there's no real bug I could
reproduce that is fixed by this patch.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
[danvet: Fix spelling mistake in the comment that Damien spotted.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 4dd6561..5e6fa77 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6140,7 +6140,10 @@
val = I915_READ(D_COMP);
val |= D_COMP_COMP_DISABLE;
- I915_WRITE(D_COMP, val);
+ mutex_lock(&dev_priv->rps.hw_lock);
+ if (sandybridge_pcode_write(dev_priv, GEN6_PCODE_WRITE_D_COMP, val))
+ DRM_ERROR("Failed to disable D_COMP\n");
+ mutex_unlock(&dev_priv->rps.hw_lock);
POSTING_READ(D_COMP);
ndelay(100);
@@ -6182,7 +6185,10 @@
val = I915_READ(D_COMP);
val |= D_COMP_COMP_FORCE;
val &= ~D_COMP_COMP_DISABLE;
- I915_WRITE(D_COMP, val);
+ mutex_lock(&dev_priv->rps.hw_lock);
+ if (sandybridge_pcode_write(dev_priv, GEN6_PCODE_WRITE_D_COMP, val))
+ DRM_ERROR("Failed to enable D_COMP\n");
+ mutex_unlock(&dev_priv->rps.hw_lock);
POSTING_READ(D_COMP);
val = I915_READ(LCPLL_CTL);