Skip to content

Deadline gets permanently skewed after sleep, cursor is immovable

Affected version

Main commit ae35c1ef

Bug summary

After wakeup from sleep the cursor is immovable.

Steps to reproduce

  1. Log in, verify that deadline evasion is used
  2. sleep machine
  3. wakeup, cursor is stuck 99.9%, non-cursor updates still work

What happened

Stuck cursor updates.

Relevant logs, screenshots, screencasts etc.

KMS_DEADLINE: Missed deadline by 2305843009213688212µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213687768µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213688471µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213688291µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213687704µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213688280µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213688919µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213688225µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213688310µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213687732µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213689408µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213688331µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213689495µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213688302µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213687882µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213692617µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213688161µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213689008µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213687744µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213688283µs, skipping by 6944µs
KMS_DEADLINE: Missed deadline by 2305843009213688235µs, skipping by 6944µs

A quick and totally uninformed look at this I think the code only adjusts for a single missed refresh. What happens if many refreshes/deadlines were missed? I did the following quick&dirty that makes the cursor behave after sleep:

--- a/src/backends/native/meta-kms-crtc.c
+++ b/src/backends/native/meta-kms-crtc.c
@@ -680,6 +680,9 @@ meta_kms_crtc_determine_deadline (MetaKmsCrtc  *crtc,
 
           next_presentation_us += refresh_interval_us;
           next_deadline_us += refresh_interval_us;
+          if (now_us > next_deadline_us){
+            next_deadline_us += now_us - next_deadline_us;
+          }
         }
     }

Thoughts?