drm/i915: Mask LPSP to get PSR working even with Power Well in use by audio.
authorRodrigo Vivi <rodrigo.vivi@gmail.com>
Thu, 3 Oct 2013 16:31:26 +0000 (13:31 -0300)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Thu, 3 Oct 2013 18:07:17 +0000 (20:07 +0200)
commit0cc4b69960f3d1231023ad5de6cacbc1fbee2a88
tree58ca135979734121e5f49a9184ac1c591af48e4e
parentf3fc4884ebe6ae649d3723be14b219230d3b7fd2
drm/i915: Mask LPSP to get PSR working even with Power Well in use by audio.

Power Well in use forces constantly PSR to exit.
On recent Kernel I noticed that PSR Performance Counter was always 0
indicating that PSR was never really achieved.
By masking LPSP, PSR can work normally and save power on Haswell.

Two bugs had been raised with PSR flag enabled:
- "Screen flickers when booted by enabling PSR in the kernel (i915.enable_psr=1) , the system is booting to a gray screen."
- "When booting the DUT with PSR feature enabled in the kernel (i915.enable_psr=1) , the system is booting to a gray screen."

Both bugs has been fixed by this patch.

v2: proper comment for -fixes

Tested-by: Selvaraj, Elavarasan <elavarasanx.selvaraj@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/intel_dp.c