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authorJesse Barnes <jbarnes@virtuousgeek.org>2009-05-05 16:03:48 -0700
committerEric Anholt <eric@anholt.net>2009-05-14 16:00:27 -0700
commit802c7eb646848d769a07704c16f7a3bbec9e5829 (patch)
parent0ba0e9e1f173a59ba402a253d356612c821b7a14 (diff)
drm/i915: sanity check IER at wait_request time
We might sleep here anyway so I hope an extra uncached read is ok to add. In #20896 we found that vbetool clobbers the IER. In KMS mode this is particularly bad since we don't set the interrupt regs late (in EnterVT), so we'd fail to get *any* interrupts at all after X started (since some distros have scripts that call vbetool at X startup apparently). So this patch checks IER at wait_request time, and re-enables interrupts if it's been clobbered. In a proper config this check should never be triggered. This is really a distro issue, but having a sanity check is nice, as long as it doesn't have a real performance hit. Tested-by: Mateusz Kaduk <mateusz.kaduk@gmail.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> [anholt: Moved the check inside of the sleeping case to avoid perf cost] Signed-off-by: Eric Anholt <eric@anholt.net>
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index ee896d91c5bc..b189b49c7602 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1691,11 +1691,20 @@ static int
i915_wait_request(struct drm_device *dev, uint32_t seqno)
drm_i915_private_t *dev_priv = dev->dev_private;
+ u32 ier;
int ret = 0;
BUG_ON(seqno == 0);
if (!i915_seqno_passed(i915_get_gem_seqno(dev), seqno)) {
+ ier = I915_READ(IER);
+ if (!ier) {
+ DRM_ERROR("something (likely vbetool) disabled "
+ "interrupts, re-enabling\n");
+ i915_driver_irq_preinstall(dev);
+ i915_driver_irq_postinstall(dev);
+ }
dev_priv->mm.waiting_gem_seqno = seqno;
ret = wait_event_interruptible(dev_priv->irq_queue,