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[v5,2/2] drm/i915/dp: Extend BDW DP audio workaround to GEN9 platforms

Message ID 1478117601-19122-1-git-send-email-dhinakaran.pandiyan@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dhinakaran Pandiyan Nov. 2, 2016, 8:13 p.m. UTC 
According to BSpec, cdclk for BDW has to be not less than 432 MHz with DP
audio enabled, port width x4, and link rate HBR2 (5.4 GHz). With cdclk less
than 432 MHz, enabling audio leads to pipe FIFO underruns and displays
cycling on/off.

Let's apply this work around to GEN9 platforms too, as it fixes the same
issue.

v2: Move drm_device to drm_i915_private conversion

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97907
Cc: stable@vger.kernel.org
Cc: Libin Yang <libin.yang@linux.intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 37483ee..0d95a2e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -10264,8 +10264,10 @@  static void bxt_modeset_commit_cdclk(struct drm_atomic_state *old_state)
 static int bdw_adjust_min_pipe_pixel_rate(struct intel_crtc_state *crtc_state,
 					  int pixel_rate)
 {
+	struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
+
 	/* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
-	if (crtc_state->ips_enabled)
+	if (IS_BROADWELL(dev_priv) && crtc_state->ips_enabled)
 		pixel_rate = DIV_ROUND_UP(pixel_rate * 100, 95);
 
 	/* BSpec says "Do not use DisplayPort with CDCLK less than
@@ -10307,7 +10309,7 @@  static int ilk_max_pixel_rate(struct drm_atomic_state *state)
 
 		pixel_rate = ilk_pipe_pixel_rate(crtc_state);
 
-		if (IS_BROADWELL(dev_priv))
+		if (IS_BROADWELL(dev_priv) || IS_GEN9(dev_priv))
 			pixel_rate = bdw_adjust_min_pipe_pixel_rate(crtc_state,
 								    pixel_rate);