On Thu, May 14, 2015 at 09:49:52AM -0400, Alex Deucher wrote: > On Tue, May 12, 2015 at 8:04 PM, Dave Jones <davej@xxxxxxxxxxxxxxxxx> wrote: > > On Mon, May 11, 2015 at 03:59:55PM -0400, Alex Deucher wrote: > > > > > > I tried tweaking the delays in drm_dp_link_train_clock_recovery_delay, without any noticable > > > > difference. Is there something else I can try to make it try harder before giving up? > > > > > > > > > > Can you attach your boot dmesg output with drm.debug=0xf set? > > > > > > You might also check the dpcd values in the driver during boot up and > > > link training. There appears to be an issue where that data gets > > > corrupted in some cases: > > > https://bugs.freedesktop.org/show_bug.cgi?id=73530 > > > > I tried both the 'disable spread spectrum' and 'grab dpcd info from vbios for eDP' > > patches from that bug. Again, no obvious difference. > > > > Log from kernel with both applied attached. > > > > Also a log file from after I woke up the LCD when it was in sleep mode. > > > > Something else curious is how it only discovers a maximum mode from the LCD > > of 1024x768. > > I looks like the monitor is not responding. I'm not entirely sure > what's going on. I posted a new debugging patch on the bug report > that will dump the dpcd at various times to see if and when it's > getting corrupt. Fixing that should at least get the monitor to come > up reliably (assuming you are experiencing the same issue). Thanks to some back-and-forth on irc, airlied got this mostly working. The working combo seems to be.. - Switch monitor to DP 1.2 - boot with radeon.mst=1 - apply the patch below With all that, it boots up, and X starts up in 2560x1440 like it should. The only remaining problem is there are some visible glitches, mostly noticable while scrolling a terminal. Happy to continue applying further debug patches if you have any more ideas. thanks, Dave diff --git a/drivers/gpu/drm/radeon/radeon_dp_auxch.c b/drivers/gpu/drm/radeon/radeon_dp_auxch.c index bf1fecc6cceb..3b401cc8d209 100644 --- a/drivers/gpu/drm/radeon/radeon_dp_auxch.c +++ b/drivers/gpu/drm/radeon/radeon_dp_auxch.c @@ -30,7 +30,6 @@ AUX_SW_RX_HPD_DISCON | \ AUX_SW_RX_PARTIAL_BYTE | \ AUX_SW_NON_AUX_MODE | \ - AUX_SW_RX_MIN_COUNT_VIOL | \ AUX_SW_RX_INVALID_STOP | \ AUX_SW_RX_SYNC_INVALID_L | \ AUX_SW_RX_SYNC_INVALID_H | \ _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
