On Fri, Apr 25, 2014 at 10:06 AM, Daniel Vetter <daniel@xxxxxxxx> wrote: > On Thu, Apr 24, 2014 at 06:22:59PM -0300, Paulo Zanoni wrote: >> From: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> >> >> We still have way too many bugs with DP link training. We keep >> switching between "narrow and fast" and "wide and slow", we recently >> added 5GHz support, and whenever there's a bug report, we have to ask >> people to apply patches and test them. >> >> Wouldn't it be so much better if we could just ask them to boot with >> some specific Kernel boot option instead of applying a patch? This >> will move the situation from "i915.ko is completely broken!" to >> "i915.ko's default values are broken, but there's an option I can set >> to fix it, so I won't need to learn how to compile a Kernel!". >> >> Some useful values: >> - i915.dp_link_train_policy=1 for "wide and slow" >> - i915.dp_link_train_policy=0x120 for DP_LINK_BW_2_7 and 2 lanes, >> which should be able to fit 1920x1080@60Hz and 24bpp >> - i915.dp_link_train_policy=0x210 to force DP 5GHz testing on >> not-so-huge modes >> >> The default behavior is still the same. >> >> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> > > Yeah, I like this. I'll sign up Todd to review this all. Now with Todd actually cc'ed. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
