drm/i915/dp: try to read receiver capabilities 3 times when detecting
authorJesse Barnes <jbarnes@virtuousgeek.org>
Thu, 7 Jul 2011 18:11:00 +0000 (11:11 -0700)
committerKeith Packard <keithp@keithp.com>
Thu, 7 Jul 2011 20:38:44 +0000 (13:38 -0700)
commit899526d9a73fda47516cf11ccb3467ad6702f568
treed4bdec27956e40aaa9209da438cea6ae3ef8f7f0
parent59cd09e1aea3ac6eb15b45e5d2261a63ecb1799c
drm/i915/dp: try to read receiver capabilities 3 times when detecting

If ->detect is called too soon after a hot plug event, the sink may not
be ready yet.  So try up to 3 times with 1ms sleeps in between tries to
get the data (spec dictates that receivers must be ready to respond within
1ms and that sources should try 3 times).

See section 9.1 of the 1.1a DisplayPort spec.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
drivers/gpu/drm/i915/intel_dp.c