Created attachment 81912 [details] dmesg with drm.debug=0xe in kernel command line I have a DELL XPS13 laptop and an external monitor. They used to work well on linux kernel 3.8. Recently, I upgraded to kernel 3.9 and found the resolution of the external monitor could not be configured correctly. I checked kern.log file and found a lot of error messages look this: Jul 2 15:27:40 debian kernel: [ 39.181113] [drm:intel_dp_i2c_aux_ch] *ERROR* too many retries, giving up I downloaded the latest kernel from drm-intel-nightly (drm-intel-a59485486882b9867bdcb1fe41cfdcba291c6585,July2nd,2013). However, the issue is still there. The dmesg information with drm.debug=0xe is attached. Since this issue was also reported by others and it was there for more than three months, hope it can be set as a high priority investigation from the development team. Please let me know if you want me to try more patches. Thanks, Wei
Hi there, I just installed linux-image-3.9-1-amd64 in Debian and the resolution was configured correctly with it although the error messages were still there. It seems that I missed somethings in the self-compiled kernel. Besides, the error message and the capability to detect correct resolution may not be related. Thanks, Wei
Note the dmesg doesn't actually contain drm.debug=0xe. Those errors look like they recover each time, so it will be useful to see the complete debug dmesg.
Hi Chris, Sorry for the confusion. I just captured it again. BTW,I found the resolution could not be consistently detected even with debian's default kernel (3.9). I have to click the "detect" button multiple times before it can get the correct resolution. Regards, Wei
Created attachment 81973 [details] dmesg with drm.debug=0xe before plugin the external monitor
Created attachment 81974 [details] dmesg with drm.debug=0xe after plugin the external monitor
From the dmesg it seems that the laptop's DP port is a branch device. The error looks similar to the one in bug 60263, could you give a try to the fix attached there ('drm/i915: Don't fallback to ddc probe if downstream port is dummy')?
Ping? Imre's patch solved a few similar issues, it would be good to test.
Wei, we've merged a number of DP link training fixes to drm-intel-nightly branch of [1]. Please test and report back. Thanks. [1] git://people.freedesktop.org/~danvet/drm-intel
bump
I did not see the issue anymore. Thanks, Wei On Mon, Nov 18, 2013 at 4:38 PM, <bugzilla-daemon@freedesktop.org> wrote: > *Comment # 9 <https://bugs.freedesktop.org/show_bug.cgi?id=66521#c9> on > bug 66521 <https://bugs.freedesktop.org/show_bug.cgi?id=66521> from Jesse > Barnes <jbarnes@virtuousgeek.org> * > > bump > > ------------------------------ > You are receiving this mail because: > > - You reported the bug. > >
Yay, progress! Thanks for reporting back and please reopen when this shows up again.
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