On Mon, May 11, 2015 at 03:59:55PM -0400, Alex Deucher wrote:
 
 > >  >  > The link training with the monitor seems to fail periodically.  You may have to play with the timing in the link training sequence.  It looks like you also have some power management related issues.  Does booting with radeon.dpm=0 on the kernel command line in grub help?  Also does the monitor support audio?  You might also try radeon.audio=0.
 > >  >
 > >  > Pretty much the same story with those options..
 > >  >
 > >  > [    8.162285] [drm:si_dpm_set_power_state [radeon]] *ERROR* si_enable_smc_cac failed
 > >  > [    8.170753] [drm:radeon_dp_link_train [radeon]] *ERROR* displayport link status failed
 > >  > [    8.170778] [drm:radeon_dp_link_train [radeon]] *ERROR* clock recovery failed
 > >  >
 > >  > I did manage to get it to display something for a while. By disabling DP1.2 with the
 > >  > LCDs OSD, but then it would only do a maximum of 1024x768. And after a reboot,
 > >  > I saw the same messages above, and straight to power saving.
 > >
 > > 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?

Sure. Attached.  I noticed some of the printks are garbled.
Hopefully the important parts lie elsewhere.

 > 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

Hm, I'll try out some of the patches in that report later (Assuming they aren't
already in the 4.1rc kernel)

thanks for the pointers.

	Dave