Workaround to avoid intermittent aux channel failures, per spec change.

Signed-off-by: Jani Nikula <jani.nik...@intel.com>

---

Untested.
---
 drivers/gpu/drm/i915/intel_dp.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 482b5e5..5fec183 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -344,7 +344,10 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
         * Note that PCH attached eDP panels should use a 125MHz input
         * clock divider.
         */
-       if (is_cpu_edp(intel_dp)) {
+       if (dev_priv->pch_id == INTEL_PCH_LPT_DEVICE_ID_TYPE) {
+               /* Workaround for non-ULT HSW */
+               aux_clock_divider = 74;
+       } else if (is_cpu_edp(intel_dp)) {
                if (HAS_DDI(dev))
                        aux_clock_divider = intel_ddi_get_cdclk_freq(dev_priv) 
>> 1;
                else if (IS_VALLEYVIEW(dev))
-- 
1.7.10.4

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