https://bugs.kde.org/show_bug.cgi?id=526438
Bug ID: 526438
Summary: DDC/CI causes DisplayPort output to be removed and
re-added repeatedly (Samsung Odyssey G5 "LS32AG55x"
not in s_brokenDdcCi blocklist)
Classification: Plasma
Product: plasmashell
Version First 6.7.5
Reported In:
Platform: Fedora RPMs
OS: Linux
Status: REPORTED
Severity: normal
Priority: NOR
Component: Power management & brightness
Assignee: [email protected]
Reporter: [email protected]
Target Milestone: 1.0
Similar to bug 494522 (fixed in KWin 6.4.1 via ca4b2c7d by blocklisting EDID
names), but my monitor's EDID name is LS32AG55x, which is not in s_brokenDdcCi
(currently only "Odyssey G5" and "LS24D60xU" in src/core/backendoutput.cpp), so
DDC/CI remains enabled and the problem persists on Plasma 6.7.5.
Setup: Fedora 44, Plasma 6.7.5 / KWin 6.7.5 Wayland, NVIDIA RTX 2060 SUPER
(driver 615.71.09), Samsung Odyssey G5 32" (LS32AG55x) on DisplayPort,
2560x1440@165.
Symptom: Multiple times per day (since at least March), every Qt app
simultaneously logs "There are no outputs - creating placeholder screen" — KWin
removes and re-adds the only output. Immediately before each event, powerdevil
logs DDC/i2c retries ("Retrying i2c_check_edid_exists_by_dh",
"ddca_get_non_table_vcp_value -5", "Locked bus /dev/i2c-8 after N tries").
kwinoutputconfig.json shows "allowDdcCi": true, "detectedDdcCi": true.
Effect: after each removal/re-add, desktop containment input dies
(right-click/rubber band) until relogin.
Ask: add LS32AG55x to s_brokenDdcCi.
Workaround that confirms DDC involvement: disabling DDC/CI for the output stops
the churn.
--
You are receiving this mail because:
You are watching all bug changes.
