drm/i915/edp: Add WaKVMNotificationOnConfigChange:bdw
authorMika Kuoppala <mika.kuoppala@linux.intel.com>
Tue, 7 Jun 2016 14:19:02 +0000 (17:19 +0300)
committerMika Kuoppala <mika.kuoppala@intel.com>
Wed, 8 Jun 2016 13:23:09 +0000 (16:23 +0300)
commit17e0adf079a3bf2ba16880f6d5473b4ca7881545
tree9afa0952a1e4960fc11c95d8c9989583861e0bf4
parent9498dba7b4ffe40a1e2b23d7718b77e49841248f
drm/i915/edp: Add WaKVMNotificationOnConfigChange:bdw

According to bspec this workaround helps to reduce lag and improve
performance on edp.

Documentation suggests this for bdw and all gen9. However evidence
shows that this register is missing on gen9 and causing unclaimed mmio
access if we access it. So apply to bdw only where the reg
exists and can hold its value.

v2: drop skl

References: HSD#2134579
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465309159-30531-11-git-send-email-mika.kuoppala@intel.com
drivers/gpu/drm/i915/i915_reg.h
drivers/gpu/drm/i915/intel_pm.c