• Chris Wilson's avatar
    drm/i915: Use PM QoS to prevent C-State starvation of gen3 GPU · b0b544cd
    Chris Wilson authored
    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: default avatarChris Wilson <chris@chris-wilson.co.uk>
    b0b544cd
i915_irq.c 49.9 KB