drm/i915: Suppress spurious CPU FIFO underruns on ILK-IVB
authorVille Syrjälä <ville.syrjala@linux.intel.com>
Fri, 20 Nov 2015 20:09:18 +0000 (22:09 +0200)
committerVille Syrjälä <ville.syrjala@linux.intel.com>
Tue, 24 Nov 2015 14:13:04 +0000 (16:13 +0200)
commit3860b2ecfc96251455091739b92217e4f01b96c2
treee050c03502ab7425d47328d73161bfe4d5a25a39
parentb6e4d53490504ee43a765e71a8fd8337af137623
drm/i915: Suppress spurious CPU FIFO underruns on ILK-IVB

We still get spurious pipe underruns on ILK/SNB/IVB under two
circumstances when dealing with PCH ports:
* When the pipe has been disabled, but FDI RX/TX is still enabled
* During FDI link training

Both cases seem to happen at least when we do VGA+HDMI cloning
from the same pipe. I don't think I've seen them when not cloning,
but can't be 100% sure.

Disable underrun reporting around those places to eliminate the
dmesg errors.

Testcase: igt/kms_setmode/basic-clone-single-crtc
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448050160-14124-1-git-send-email-ville.syrjala@linux.intel.com
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
drivers/gpu/drm/i915/intel_display.c