patch-2.4.13 linux/drivers/char/drm/drm_drv.h

• Lines: 34
• Date: Sun Oct 21 10:40:36 2001
• Orig file: v2.4.12/linux/drivers/char/drm/drm_drv.h
• Orig date: Sun Sep 23 11:40:57 2001

diff -u --recursive --new-file v2.4.12/linux/drivers/char/drm/drm_drv.h linux/drivers/char/drm/drm_drv.h
@@ -1047,6 +1047,25 @@
 
 	atomic_inc( &dev->counts[_DRM_STAT_UNLOCKS] );
 
+#if __HAVE_KERNEL_CTX_SWITCH
+	/* We no longer really hold it, but if we are the next
+	 * agent to request it then we should just be able to
+	 * take it immediately and not eat the ioctl.
+	 */
+	dev->lock.pid = 0;
+	{
+		__volatile__ unsigned int *plock = &dev->lock.hw_lock->lock;
+		unsigned int old, new, prev, ctx;
+
+		ctx = lock.context;
+		do {
+			old  = *plock;
+			new  = ctx;
+			prev = cmpxchg(plock, old, new);
+		} while (prev != old);
+	}
+	wake_up_interruptible(&dev->lock.lock_queue);
+#else
 	DRM(lock_transfer)( dev, &dev->lock.hw_lock->lock,
 			    DRM_KERNEL_CONTEXT );
 #if __HAVE_DMA_SCHEDULE
@@ -1061,6 +1080,7 @@
 			DRM_ERROR( "\n" );
 		}
 	}
+#endif /* !__HAVE_KERNEL_CTX_SWITCH */
 
 	unblock_all_signals();
 	return 0;