The pipestat fields affect reporting of all vblank-related interrupts, so we
have to reset them during the irq_handler, and while enabling vblank
interrupts. Otherwise, if a pipe status field had been set to non-zero
before enabling reporting, we would never see an interrupt again.
This patch adds i915_enable_pipestat and i915_disable_pipestat to abstract
out the steps needed to change the reported interrupts.
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This adds the support necessary for allowing ACPI backlight control to
work on some newer Intel-based graphics systems. Tested on Thinkpad T61
and HP 2510p hardware.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Dave Airlie <airlied@linux.ie>
