From 0289d87d9cf40b17ced3fd13923dcc8e93b77b60 Mon Sep 17 00:00:00 2001 From: Jung-uk Kim Date: Thu, 29 Aug 2013 18:36:47 +0000 Subject: [PATCH] Fix atomic operations on context_flag without altering semantics. --- sys/dev/drm2/drm_context.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/sys/dev/drm2/drm_context.c b/sys/dev/drm2/drm_context.c index c844a39dff2c..9ca941e6a8a4 100644 --- a/sys/dev/drm2/drm_context.c +++ b/sys/dev/drm2/drm_context.c @@ -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 *dev, int old, int new) 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 drm_device *dev, int new) /* 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; }