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authorVille Syrjälä <ville.syrjala@linux.intel.com>2015-10-30 19:23:22 +0200
committerVille Syrjälä <ville.syrjala@linux.intel.com>2015-11-10 16:23:28 +0200
commit0c241d5b2770d4a50d3367ed591d0d0236b69b51 (patch)
tree083cd90810c292e3bed7295d5a1caa4cafd6ab0b /drivers/gpu/drm/i915/intel_dp.c
parentc465613bc97ed996f2278116c79d2c6adec3998d (diff)
downloadlinux-0c241d5b2770d4a50d3367ed591d0d0236b69b51.tar.bz2
drm/i915: Disable FIFO underrun reporting around IBX transcoder B workaround
Doing the IBX transcoder B workaround causes underruns on pipe/transcoder A. Just hide them by disabling underrun reporting for pipe A around the workaround. It might be possible to avoid the underruns by moving the workaround to be applied only when enabling pipe A. But I was too lazy to try it right now, and the current method has been proven to work, so didn't want to change it too hastily. Note that this can re-enable underrun reporting on pipe A if was already disabled due to a previous actual underrun. But that's OK, we may just get a second underrun report if another real underron occurrs on pipe A. v2: Note that pipe A underruns can get re-enabled due to this (Jani) Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v1) Link: http://patchwork.freedesktop.org/patch/msgid/1446225802-11180-1-git-send-email-ville.syrjala@linux.intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp.c')
-rw-r--r--drivers/gpu/drm/i915/intel_dp.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 5264887311f1..278f025f4b20 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3655,6 +3655,13 @@ intel_dp_link_down(struct intel_dp *intel_dp)
* matching HDMI port to be enabled on transcoder A.
*/
if (HAS_PCH_IBX(dev) && crtc->pipe == PIPE_B && port != PORT_A) {
+ /*
+ * We get CPU/PCH FIFO underruns on the other pipe when
+ * doing the workaround. Sweep them under the rug.
+ */
+ intel_set_cpu_fifo_underrun_reporting(dev_priv, PIPE_A, false);
+ intel_set_pch_fifo_underrun_reporting(dev_priv, PIPE_A, false);
+
/* always enable with pattern 1 (as per spec) */
DP &= ~(DP_PIPEB_SELECT | DP_LINK_TRAIN_MASK);
DP |= DP_PORT_EN | DP_LINK_TRAIN_PAT_1;
@@ -3664,6 +3671,10 @@ intel_dp_link_down(struct intel_dp *intel_dp)
DP &= ~DP_PORT_EN;
I915_WRITE(intel_dp->output_reg, DP);
POSTING_READ(intel_dp->output_reg);
+
+ intel_wait_for_vblank_if_active(dev_priv->dev, PIPE_A);
+ intel_set_cpu_fifo_underrun_reporting(dev_priv, PIPE_A, true);
+ intel_set_pch_fifo_underrun_reporting(dev_priv, PIPE_A, true);
}
msleep(intel_dp->panel_power_down_delay);