Several compliance tests require that follow-up AUX transactions (after a
failure or no response) are not resent sooner than 400us later. Add a 400us
delay to the response time of any failed transaction to account for this.
Signed-off-by: Todd Previte <tprevite@xxxxxxxxx>
---
drivers/gpu/drm/i915/intel_dp.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 3bd1780..43fcabe 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -561,8 +561,12 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
DP_AUX_CH_CTL_RECEIVE_ERROR);
if (status & (DP_AUX_CH_CTL_TIME_OUT_ERROR |
- DP_AUX_CH_CTL_RECEIVE_ERROR))
+ DP_AUX_CH_CTL_RECEIVE_ERROR)) {
+ /* 400us delay between transactions for errors/timeouts
+ required for DP compliance testing */
+ udelay(400);
continue;
+ }
if (status & DP_AUX_CH_CTL_DONE)
break;
}
--
1.9.1
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