Bug 200667
| Summary: | [AMDGPU] stacktrace in dmesg, starting at drm_dp_i2c_do_msg | ||
|---|---|---|---|
| Product: | Drivers | Reporter: | Christian Widmer (cwidmer) |
| Component: | Video(DRI - non Intel) | Assignee: | drivers_video-dri |
| Status: | NEW --- | ||
| Severity: | normal | CC: | alexdeucher, harry.wentland |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 4.17.10 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: |
Full dmesg output from kernel 4.18-r6
Kernel configuration lspci |
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Created attachment 277571 [details]
Kernel configuration
Created attachment 277573 [details]
lspci
I am using an RX 580.
I might add simply booting the kernel is all that is needed to trigger the issue. The stacktraces automatically appear during the boot process. Can you bisect? The bisect identified commit 9168c089a2122606e2c01f6fbeda85ff950ac189 (Revert "drm/amd/display: Don't return ddc result and read_bytes in same return value", upstream commit 5292221d6ddfed75e5b46cd42237a677094b99f3). And a quick test with reverting this change in my distribution's 4.17.10 kernel and in the mainline 4.18-rc6 kernel indeed made the stacktrace disappear. The warning is harmless. As per the commit message, this is fixed properly for 4.19 with the following patches:
This breaks DDC in certain cases. Revert for 4.18 and previous kernels.
For 4.19, this is fixed with the following more extensive patches:
drm/amd/display: Serialize is_dp_sink_present
drm/amd/display: Break out function to simply read aux reply
drm/amd/display: Return aux replies directly to DRM
drm/amd/display: Right shift AUX reply value sooner than later
drm/amd/display: Read AUX channel even if only status byte is returned
For the sake of completeness I have just tested linux-next which contains all those patches and the warning is indeed gone. Thank you for your responses! As expected, the warning is indeed gone with the recently released stable kernel 4.19. |
Created attachment 277569 [details] Full dmesg output from kernel 4.18-r6 When I changed my kernel from 4.17.9 to 4.17.10 (both patched with the Gentoo patchset), a stacktrace started to appear in the kernel messages. To check whether this is still an issue in mainline and not related to the distribution kernel, I tried 4.18-r6 which also shows the issue.