https://bugzilla.kernel.org/show_bug.cgi?id=67121
Bug ID: 67121 Summary: Broken suspend/resume with radeon/KMS on RS482M Product: Drivers Version: 2.5 Kernel Version: 3.12.5 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Video(DRI - non Intel) Assignee: drivers_video-dri@kernel-bugs.osdl.org Reporter: adi@drcomp.erfurt.thur.de Regression: No
Hi!
This report is somewhat similar to https://bugzilla.kernel.org/show_bug.cgi?id=43441, but since it's about a different card and slightly different focus, I didn't want to pollute the other bug report with potentially misleading information.
Here's the problem: First suspend/resume cycle works, second may fail at either suspend or resume, the machine simply hangs. Sometimes, just sometimes, the second cycle might fully succeed, in this case, the third attempt is bound to fail.
After the first suspend/resume cycle, removing AC power will cripple the output as seen in these videos:
http://adi.loris.tv/radeon-kms1.mp4
http://adi.loris.tv/radeon-kms2.mp4
Plugging AC back in will fix the issue until I remove the power supply again, resulting in the same distortion. Note that AC plug/removal has to take place when the machine is running, those events don't do a thing during suspend, so something is clearly acting to these ACPI events, though I couldn't spot any code in radeon that handles power events on such an old card.
I'm going to attach five register dumps taken in the following sequence:
1. Fresh boot with AC plugged in (freshboot-powered) 2. Now let's remove the AC while running, no reboot (freshboot-unpowered) 3. Now let's put the AC back in (freshboot-powered2) 4. Suspend/Resume while AC stays active (resumed-powered) 5. Now remove AC again (resumed-unpowered) --> distortion
While I think both aspects are related, I care more about the suspend/resume than the distortion.
Note that UMS shows neither distortion nor any suspend/resume problems.
Finally, let me point out that it's always been like this. I had modeset=0 for years (roughly since March 2011).