drm/i915: Avoid a double-read of PCH_IIR during interrupt handling
authorChris Wilson <chris@chris-wilson.co.uk>
Wed, 9 May 2012 20:45:43 +0000 (21:45 +0100)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Thu, 10 May 2012 09:51:30 +0000 (11:51 +0200)
commit9adab8b5a7fde248504f484e197589f3e3c922e2
treee1881a35e6824fcaee50e36c5d653a1429857e04
parent59de3295adaf9503e91e7e6d323cf9becef600de
drm/i915: Avoid a double-read of PCH_IIR during interrupt handling

Currently the code re-reads PCH_IIR during the hotplug interrupt
processing. Not only is this a wasted read, but introduces a potential
for handling a spurious interrupt as we then may not clear all the
interrupts processed (since the re-read IIR may contains more interrupts
asserted than we clear using the result of the original read).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: stable@kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/i915_irq.c