On Tue, 30 Oct 2012, Jani Nikula <jani.nikula at intel.com> wrote: > Hi Ted - > > On Tue, 30 Oct 2012, Theodore Ts'o <tytso at mit.edu> wrote: >> I recently upgraded to 3.6.3, and my Lenovo X230 has stopped being able >> to work with an HP ZR30w 30" 2560x1600 display. I saw the following >> messages in the dmesg: >> >> [drm:ivb_manual_fdi_link_train] *ERROR* FDI train 1 fail! >> [drm:ivb_manual_fdi_link_train] *ERROR* FDI train 2 fail! >> >> .. which I didn't see before; the exact same mini-displayport to >> displayport cable connecting the same Lenovo X230 laptop to exactly the >> same ZRW 30 display worked just fine with the 3.6.0 kernel. >> >> So I bisected the problem, and found the following commit. Reverting >> this commit made the problem go away. Maybe we should revert >> 0c96c65b48fb in mainline? > > Thanks for bisecting. However, the commit does fix a bug for some people > out there, which is why it's been backported to stable. Without it, we > fail to dither when there is not enough bandwidth in the DP link. My > guess is that this brings up another bug that affects you, and IMHO we'd > be better off debugging this than reverting. > >> Let me know if you'd like me to do any further debugging. > > Something to try would be the latest i915.ko driver [1], which I believe > has some link training changes, and/or posting the dmesg with > drm.debug=0xe module parameter. > > BR, > Jani. > > > [1] drm-intel-next-queued branch at > git://people.freedesktop.org/~danvet/drm-intel
Hmm, actually not. Either drm-intel-fixes branch, or Linus' master. Daniel, 'git tag --contains 0c96c65b48fba3ffe9822a554cbc0cd610765cd5' says the commit is upstream since v3.7-rc1, and you backmerged v3.7-rc2 to drm-intel-next-queued with c2fb7916927e989ea424e61ce5fe617e54878827, but the adjusted_mode fix is nowhere to be seen. Did something go wrong with the backmerge, or am I missing something? BR, Jani.
