[Intel-gfx] [PATCH 2/2] drm/i915: Wait for pipe to start on i830 as well

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

We should make sure the pipe has fully started when we enable it from
the i830 "power well". Otherwise theoretically i830 could also hit
problems with vblank timestamps jumping around (since we skip the
wait during modeset on i830). Additionally moving planes between the
pipes etc. might not work correctly until both pipes are actually up and
running.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 810b1147a0ac..467f72df9db3 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -14704,6 +14704,9 @@ void i830_enable_pipe(struct drm_i915_private *dev_priv, enum pipe pipe)
 
 	I915_WRITE(PIPECONF(pipe), PIPECONF_ENABLE | PIPECONF_PROGRESSIVE);
 	POSTING_READ(PIPECONF(pipe));
+
+	if (wait_for(pipe_dsl_stopped(dev_priv, pipe, false), 100))
+		DRM_ERROR("pipe %c on wait timed out\n", pipe_name(pipe));
 }
 
 void i830_disable_pipe(struct drm_i915_private *dev_priv, enum pipe pipe)
-- 
2.13.6