On 14 July 2014 10:46, Dave Airlie <airlied@xxxxxxxxx> wrote: > On 15 May 2014 18:58, Jani Nikula <jani.nikula@xxxxxxxxx> wrote: >> On Wed, 14 May 2014, Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> wrote: >>> We do have to continue the investigation on the link training side, but >>> since 76711 is a critical I'm completely in favor of this workaround for >>> now. >>> >>> I just tested and it worked very well here, so: >>> >>> Tested-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> >>> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> >> >> Pushed to -fixes, thanks for the review and testing. >> >> BR, >> Jani. >> >>> >>> >>> On Wed, May 14, 2014 at 6:02 AM, Jani Nikula <jani.nikula@xxxxxxxxx> wrote: >>> >>>> There are certain BDW high res eDP machines that regressed due to >>>> >>>> commit 38aecea0ccbb909d635619cba22f1891e589b434 >>>> Author: Daniel Vetter <daniel.vetter@xxxxxxxx> >>>> Date: Mon Mar 3 11:18:10 2014 +0100 >>>> >>>> drm/i915: reverse dp link param selection, prefer fast over wide again >>>> >>>> The commit lead to 2 lanes at 5.4 Gbps being used instead of 4 lanes at >>>> 2.7 Gbps on the affected machines. Link training succeeded for both, but >>>> the screen remained blank with the former config. Further investigation >>>> showed that 4 lanes at 5.4 Gbps worked also. >>>> >>>> The root cause for the blank screen using 2 lanes remains unknown, but >>>> apparently the driver for a certain other operating system by default >>>> uses the max available lanes. Follow suit on Broadwell eDP, for at least >>>> until we figure out what is going on. > > Uggh, okay this lane thing is such a pita, > > On haswell the Lenovo dock in SST mode is broken by the original patch as well. > > I'm not sure we want to do IS_HASWELL here as well, > > I think we need to revert 38aecea0ccbb909d635619cba22f1891e589b434 Actually adding IS_HASWELL won't work since this problem is with a standard DP port. I'll send the reverts, though I've no idea if this another revert of a revert etc. Dave. _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
