Messages in this thread Patch in this message | | | Date | Thu, 24 Nov 2005 10:51:39 +0000 (GMT) | From | Dave Airlie <> | Subject | [git tree] drm locking fix |
| |
Hi Linus, Lee Revell reported a problem with the via driver, this patch to fix it is from DRM CVS.. can you pull the drm-linus branch from:
rsync://rsync.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6.git
diff-tree cf65f1623dd005ddfb1cbba20af3423a6c638dbe (from 33bc227e4e48ddadcf2eacb381c19df338f0a6c8) Author: Dave Airlie <airlied@starflyer.(none)> Date: Thu Nov 24 21:41:14 2005 +1100
drm: fix quiescent locking
A fix for a locking bug which is triggered when a client tries to lock with flag DMA_QUIESCENT (typically the X server), but gets interrupted by a signal. The locking IOCTL should then return an error, but if DMA_QUIESCENT succeeds it returns 0, and the client falsely thinks it has the lock. In addition The client waits for DMA_QUISCENT and possibly DMA_READY without having the lock.
From: Thomas Hellstrom Signed-off-by: Dave Airlie <airlied@linux.ie>
:100644 100644 b276ae8a6633bb836cd96ed3cd927ca3504efce0 b48a595d54eca0e9c13b0cb269b88fba6dc49f56 M drivers/char/drm/drm_lock.c diff --git a/drivers/char/drm/drm_lock.c b/drivers/char/drm/drm_lock.c --- a/drivers/char/drm/drm_lock.c +++ b/drivers/char/drm/drm_lock.c @@ -104,6 +104,10 @@ int drm_lock(struct inode *inode, struct __set_current_state(TASK_RUNNING); remove_wait_queue(&dev->lock.lock_queue, &entry);
+ DRM_DEBUG("%d %s\n", lock.context, ret ? "interrupted" : "has lock"); + if (ret) + return ret; + sigemptyset(&dev->sigmask); sigaddset(&dev->sigmask, SIGSTOP); sigaddset(&dev->sigmask, SIGTSTP); @@ -116,8 +120,12 @@ int drm_lock(struct inode *inode, struct if (dev->driver->dma_ready && (lock.flags & _DRM_LOCK_READY)) dev->driver->dma_ready(dev);
- if (dev->driver->dma_quiescent && (lock.flags & _DRM_LOCK_QUIESCENT)) - return dev->driver->dma_quiescent(dev); + if (dev->driver->dma_quiescent && (lock.flags & _DRM_LOCK_QUIESCENT)) { + if (dev->driver->dma_quiescent(dev)) { + DRM_DEBUG("%d waiting for DMA quiescent\n", lock.context); + return DRM_ERR(EBUSY); + } + }
/* dev->driver->kernel_context_switch isn't used by any of the x86 * drivers but is used by the Sparc driver. @@ -128,9 +136,7 @@ int drm_lock(struct inode *inode, struct dev->driver->kernel_context_switch(dev, dev->last_context, lock.context); } - DRM_DEBUG("%d %s\n", lock.context, ret ? "interrupted" : "has lock"); - - return ret; + return 0; }
/** - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |