https://bugs.freedesktop.org/show_bug.cgi?id=68235
--- Comment #32 from Alexandre Demers alexandre.f.demers@gmail.com --- (In reply to comment #31)
Created attachment 85989 [details] [review] testing patch
Try this patch independent from any other patches. It forces the engine and memory clocks of all performance levels within a power state to the lowest level. If it works, then try and comment out either the sclk part or the mclk part and see if either helps. That should help us narrow down whether it's a mclk problem or an sclk problem.
Running with the patch works fine over a vanilla kernel 3.12-rc1. The following works also fine: // if (pl->sclk > 25000) // pl->sclk = 25000; if (pl->mclk > 15000) pl->mclk = 15000; Which means sclk is working properly.
However, the opposite results in a blank screen before I can even get at the login screen. It seems mclk is the problematic part.