[Bug 27314] displayport link training fails on certain panels (channel equalization fails)

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=27314

--- Comment #42 from Jérémy Lal <kapouer at melix.org> 2011-05-10 18:28:22 PDT ---
I think the problem comes from the difference between BIOS run (working):
drm:radeon_dp_get_link_status], link status 11 11 80 00 00 00
[drm:radeon_dp_link_train], clock recovery at voltage 0 pre-emphasis 0
[drm:radeon_dp_get_link_status], link status 77 77 81 00 00 00
[drm:radeon_dp_link_train], channel eq at voltage 0 pre-emphasis 0

and EFI run (black screen):
[drm:radeon_dp_get_link_status], link status 00 00 00 00 11 11
[drm:dp_get_adjust_train], requested signal parameters: lane 0 voltage 0.6V
pre_emph 0dB
[drm:dp_get_adjust_train], requested signal parameters: lane 1 voltage 0.6V
pre_emph 0dB
[drm:dp_get_adjust_train], requested signal parameters: lane 2 voltage 0.6V
pre_emph 0dB
[drm:dp_get_adjust_train], requested signal parameters: lane 3 voltage 0.6V
pre_emph 0dB
[drm:dp_get_adjust_train], using signal parameters: voltage 0.6V pre_emph 0dB
[drm:radeon_dp_get_link_status], link status 00 00 00 00 22 22

Though I'm a bit weak on atombios_dp.c, i'm ready to promptly test any patch.
Last test was with kernel 2.6.39-rc6.

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.