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| author | Jesse Barnes <jbarnes@virtuousgeek.org> | 2009-05-05 16:03:48 -0700 |
|---|---|---|
| committer | Eric Anholt <eric@anholt.net> | 2009-05-14 16:00:27 -0700 |
| commit | 802c7eb646848d769a07704c16f7a3bbec9e5829 (patch) | |
| tree | 49cdcc60c01c0d0893d285423f04d39d7eabfb2b /drivers/gpu | |
| parent | 0ba0e9e1f173a59ba402a253d356612c821b7a14 (diff) | |
| download | kernel_samsung_crespo-802c7eb646848d769a07704c16f7a3bbec9e5829.zip kernel_samsung_crespo-802c7eb646848d769a07704c16f7a3bbec9e5829.tar.gz kernel_samsung_crespo-802c7eb646848d769a07704c16f7a3bbec9e5829.tar.bz2 | |
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>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem.c | 9 |
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 ee896d9..b189b49 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; i915_user_irq_get(dev); ret = wait_event_interruptible(dev_priv->irq_queue, |