]> git.karo-electronics.de Git - linux-beck.git/commit
drm/i915: Use PM QoS to prevent C-State starvation of gen3 GPU
authorChris Wilson <chris@chris-wilson.co.uk>
Sun, 9 Jan 2011 12:04:40 +0000 (12:04 +0000)
committerChris Wilson <chris@chris-wilson.co.uk>
Wed, 19 Jan 2011 12:38:26 +0000 (12:38 +0000)
commitb0b544cd37c060e261afb2cf486296983fcb56da
tree90a57f398e2fdc9b1caacaecdd43d7607dbb4a59
parentf67a559daaa0e2ba616bfe9438f202bc57bc8c72
drm/i915: Use PM QoS to prevent C-State starvation of gen3 GPU

945 class hardware has an interesting quirk in which the vblank
interrupt is not raised if the CPU is in a low power state. (We also
suspect that the memory bus is clocked to the CPU/c-state and not the
GPU so there are secondary starvation issues.) In order to prevent the
most obvious issue of the low of the vblank interrupt (stuttering
compositing that only updates when the mouse is moving) is to install a
PM QoS request to prevent low c-states whilst the GPU is active.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
drivers/gpu/drm/i915/i915_drv.h
drivers/gpu/drm/i915/i915_irq.c