svn commit: r255037 - head/sys/dev/drm2

[Jung-uk Kim]

Author: jkim
Date: Thu Aug 29 18:36:47 2013
New Revision: 255037
URL: http://svnweb.freebsd.org/changeset/base/255037

Log:
  Fix atomic operations on context_flag without altering semantics.

Modified:
  head/sys/dev/drm2/drm_context.c

Modified: head/sys/dev/drm2/drm_context.c
==============================================================================
--- head/sys/dev/drm2/drm_context.c     Thu Aug 29 17:45:13 2013        
(r255036)
+++ head/sys/dev/drm2/drm_context.c     Thu Aug 29 18:36:47 2013        
(r255037)
@@ -182,7 +182,7 @@ bad:
 
 int drm_context_switch(struct drm_device *dev, int old, int new)
 {
-       if (test_and_set_bit(0, &dev->context_flag)) {
+       if (atomic_xchg(&dev->context_flag, 1) != 0) {
                DRM_ERROR("Reentering -- FIXME\n");
                return EBUSY;
        }
@@ -190,7 +190,7 @@ int drm_context_switch(struct drm_device
        DRM_DEBUG("Context switch from %d to %d\n", old, new);
 
        if (new == dev->last_context) {
-               clear_bit(0, &dev->context_flag);
+               atomic_xchg(&dev->context_flag, 0);
                return 0;
        }
 
@@ -208,7 +208,7 @@ int drm_context_switch_complete(struct d
        /* If a context switch is ever initiated
           when the kernel holds the lock, release
           that lock here. */
-       clear_bit(0, &dev->context_flag);
+       atomic_xchg(&dev->context_flag, 0);
 
        return 0;
 }
_______________________________________________
svn-src-head@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"