drm/i915: Retry DP aux_ch communications with a different clock after failure
authorChris Wilson <chris@chris-wilson.co.uk>
Sun, 21 Jul 2013 15:00:03 +0000 (16:00 +0100)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Fri, 26 Jul 2013 17:44:53 +0000 (19:44 +0200)
commitbc86625a4ff7574d4d4dba79723457711eb784e0
treef1a0b96ba0a111ddaf5fd95e42322c0e31f53928
parentb8f102e8bf71cacf33326360fdf9dcfd1a63925b
drm/i915: Retry DP aux_ch communications with a different clock after failure

The w/a db makes the recommendation to both use a non-default value for
the initial clock and then to retry with an alternative clock for
Haswell with the Lakeport PCH.

"On LPT:H, use a divider value of 63 decimal (03Fh). If there is a
failure, retry at least three times with 63, then retry at least three
times with 72 decimal (048h)."

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/intel_dp.c