drm/i915: Fix the IBX transcoder B workarounds
Currently the IBX transcoder B workarounds are not working correctly.
Well, the HDMI one seems to be working somewhat, but the DP one is
definitely busted.
After a bit of experimentation it looks like the best way to make this
work is first disable the port on transcoder B, and then re-enable it
transcoder A, and immediately disable it again.
We can also clean up the code by noting that we can't be called without
a valid crtc. And also note that port A on ILK does not need the
workaround, so let's check for that one too.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index e3e9c98..4a87691 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -1437,6 +1437,7 @@
{
struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
struct intel_sdvo *intel_sdvo = to_sdvo(encoder);
+ struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
u32 temp;
intel_sdvo_set_active_outputs(intel_sdvo, 0);
@@ -1445,32 +1446,22 @@
DRM_MODE_DPMS_OFF);
temp = I915_READ(intel_sdvo->sdvo_reg);
- if ((temp & SDVO_ENABLE) != 0) {
- /* HW workaround for IBX, we need to move the port to
- * transcoder A before disabling it. */
- if (HAS_PCH_IBX(encoder->base.dev)) {
- struct drm_crtc *crtc = encoder->base.crtc;
- int pipe = crtc ? to_intel_crtc(crtc)->pipe : -1;
- if (temp & SDVO_PIPE_B_SELECT) {
- temp &= ~SDVO_PIPE_B_SELECT;
- I915_WRITE(intel_sdvo->sdvo_reg, temp);
- POSTING_READ(intel_sdvo->sdvo_reg);
+ temp &= ~SDVO_ENABLE;
+ intel_sdvo_write_sdvox(intel_sdvo, temp);
- /* Again we need to write this twice. */
- I915_WRITE(intel_sdvo->sdvo_reg, temp);
- POSTING_READ(intel_sdvo->sdvo_reg);
+ /*
+ * HW workaround for IBX, we need to move the port
+ * to transcoder A after disabling it to allow the
+ * matching DP port to be enabled on transcoder A.
+ */
+ if (HAS_PCH_IBX(dev_priv) && crtc->pipe == PIPE_B) {
+ temp &= ~SDVO_PIPE_B_SELECT;
+ temp |= SDVO_ENABLE;
+ intel_sdvo_write_sdvox(intel_sdvo, temp);
- /* Transcoder selection bits only update
- * effectively on vblank. */
- if (crtc)
- intel_wait_for_vblank(encoder->base.dev, pipe);
- else
- msleep(50);
- }
- }
-
- intel_sdvo_write_sdvox(intel_sdvo, temp & ~SDVO_ENABLE);
+ temp &= ~SDVO_ENABLE;
+ intel_sdvo_write_sdvox(intel_sdvo, temp);
}
}