drm/nv50-/gpio: initialise to vbios defaults during init
authorBen Skeggs <bskeggs@redhat.com>
Fri, 31 Aug 2012 00:51:20 +0000 (10:51 +1000)
committerBen Skeggs <bskeggs@redhat.com>
Fri, 31 Aug 2012 00:51:20 +0000 (10:51 +1000)
commit991083ba60f89e717e3a4175be96d48a810e9eae
tree403b41de79bdd5ad392456f56329476fc6b00542
parenta348cd5fd85dbca7260ef865c5def85929932861
drm/nv50-/gpio: initialise to vbios defaults during init

This is required to fix an issue on the Retina MBP where the eDP panel's
AUX channel isn't wired up to the HPD pin for the panel, causing our aux
code to bail out early.

From looking at various traces of the binary driver, it appears NVIDIA do
something very similar on at least all nv50+ chipsets during their
initialisation sequence.  So, hopefully this is safe.

Issue and fix initially tracked down by Ryan Bourgeois on fdo#51971.

Backported fix from reworked nouveau kernel module.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
drivers/gpu/drm/nouveau/nv50_gpio.c