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<b><a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - [BAT][SKL] igt@kms_flip@basic-flip-vs-dpms produces a dmesg-fail"
href="https://bugs.freedesktop.org/show_bug.cgi?id=101167#c12">Comment # 12</a>
on <a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - [BAT][SKL] igt@kms_flip@basic-flip-vs-dpms produces a dmesg-fail"
href="https://bugs.freedesktop.org/show_bug.cgi?id=101167">bug 101167</a>
from <span class="vcard"><a class="email" href="mailto:marta.lofstedt@intel.com" title="Marta Löfstedt <marta.lofstedt@intel.com>"> <span class="fn">Marta Löfstedt</span></a>
</span></b>
<pre>I was wondering why we don't sleep when we are timed out on the aux channel.
So, I decided to test below:
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -198,7 +198,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8
request,
* sufficient, bump to 32 which makes Dell 4k monitors happier.
*/
for (retry = 0; retry < 32; retry++) {
- if (ret != 0 && ret != -ETIMEDOUT) {
+ if (ret != 0 /*&& ret != -ETIMEDOUT*/) {
To my surprise this does NOT help.
Note:
commit e1083ff35157185b01bc0a99cb19b7cbae0fc9fa
Author: Lyude <<a href="mailto:cpaul@redhat.com">cpaul@redhat.com</a>>
Date: Wed Apr 13 10:58:30 2016 -0400
drm/dp_helper: Always wait before retrying native aux transactions
There is also a reference to a discussion about a similar issue, but this time
with docking station involved for this patch:
commit 82922da39190199260a726d7081a8ea4873e5fd6
Author: Lyude <<a href="mailto:cpaul@redhat.com">cpaul@redhat.com</a>>
Date: Wed Apr 13 10:58:31 2016 -0400
drm/dp_helper: Retry aux transactions on all errors</pre>
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