intel_cleanup_ring_buffer() calls drm_gem_object_unreference() (as opposed to drm_gem_object_unreference_unlocked()) so it needs to be called with "struct_mutex" held. If we don't hold the lock, it triggers a BUG_ON(!mutex_is_locked(&dev->struct_mutex));
I also audited the other places that call intel_cleanup_ring_buffer() and they all hold the lock so they're OK.
This was introduced in: 8187a2b70e3 "drm/i915: introduce intel_ring_buffer structure (V2)" and it's a regression from v2.6.34.
Addresses: https://bugzilla.kernel.org/show_bug.cgi?id=16247
Signed-off-by: Dan Carpenter error27@gmail.com Reported-by: Benny Halevy bhalevy@panasas.com Tested-by: Benny Halevy bhalevy@panasas.com
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index 59a2bf8..3325af1 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -128,9 +128,11 @@ static int i915_dma_cleanup(struct drm_device * dev) if (dev->irq_enabled) drm_irq_uninstall(dev);
+ mutex_lock(&dev->struct_mutex); intel_cleanup_ring_buffer(dev, &dev_priv->render_ring); if (HAS_BSD(dev)) intel_cleanup_ring_buffer(dev, &dev_priv->bsd_ring); + mutex_unlock(&dev->struct_mutex);
/* Clear the HWS virtual address at teardown */ if (I915_NEED_GFX_HWS(dev))
On Wed, 23 Jun 2010 13:19:55 +0200 Dan Carpenter error27@gmail.com wrote:
intel_cleanup_ring_buffer() calls drm_gem_object_unreference() (as opposed to drm_gem_object_unreference_unlocked()) so it needs to be called with "struct_mutex" held. If we don't hold the lock, it triggers a BUG_ON(!mutex_is_locked(&dev->struct_mutex));
I also audited the other places that call intel_cleanup_ring_buffer() and they all hold the lock so they're OK.
This was introduced in: 8187a2b70e3 "drm/i915: introduce intel_ring_buffer structure (V2)" and it's a regression from v2.6.34.
Addresses: https://bugzilla.kernel.org/show_bug.cgi?id=16247
Signed-off-by: Dan Carpenter error27@gmail.com Reported-by: Benny Halevy bhalevy@panasas.com Tested-by: Benny Halevy bhalevy@panasas.com
Reminds me, Gordon can you add module unload testing to your set of basic daily tests? To unload you need to unbind the fbcon interface first, my script is like this:
echo 0 > /sys/class/vtconsole/vtcon1/bind rmmod i915 rmmod drm_kms_helper rmmod drm modprobe i915 echo 1 > /sys/class/vtconsole/vtcon1/bind
If unload and re-load doesn't work please file a bug and see if you can bisect it.
Thanks,
On Wed, 23 Jun 2010 08:47:18 -0700, Jesse Barnes jbarnes@virtuousgeek.org wrote:
Reminds me, Gordon can you add module unload testing to your set of basic daily tests? To unload you need to unbind the fbcon interface first, my script is like this:
echo 0 > /sys/class/vtconsole/vtcon1/bind rmmod i915 rmmod drm_kms_helper rmmod drm modprobe i915 echo 1 > /sys/class/vtconsole/vtcon1/bind
To which we could even add a kmemleak check. After rmmod drm and before reloading i915: echo scan > /sys/kernel/debug/kmemleak cat /sys/kernel/debug/kmemleak > `hostname`-leaks.txt
If the output is not empty, file a bug. [Of course this means having to compile kmemleak into the kernel. The DEBUG_KMEMLEAK option is found under Kernel Hacking.] And since each generation has slightly different initialization stanzas, we need to repeat the test on all platforms.
On Wed, 23 Jun 2010 13:19:55 +0200, Dan Carpenter error27@gmail.com wrote:
intel_cleanup_ring_buffer() calls drm_gem_object_unreference() (as opposed to drm_gem_object_unreference_unlocked()) so it needs to be called with "struct_mutex" held. If we don't hold the lock, it triggers a BUG_ON(!mutex_is_locked(&dev->struct_mutex));
I also audited the other places that call intel_cleanup_ring_buffer() and they all hold the lock so they're OK.
This was introduced in: 8187a2b70e3 "drm/i915: introduce intel_ring_buffer structure (V2)" and it's a regression from v2.6.34.
Addresses: https://bugzilla.kernel.org/show_bug.cgi?id=16247
Signed-off-by: Dan Carpenter error27@gmail.com Reported-by: Benny Halevy bhalevy@panasas.com Tested-by: Benny Halevy bhalevy@panasas.com
Applied to for-linus. Thanks!
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