agp/intel: Fix wrong kunmap in i830_cleanup()

Add a missing NULL check and fix the wrong address passed to kunmap()
in i830_cleanup().

Cc: stable@kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[danvet: added cc stable]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c
index 9272c38dd3c6ce8a66e9e0d2b0a5085ddd2973a7..16a2847b7cdbfeee43c9dcd212915a2f6b500711 100644 (file)
--- a/drivers/char/agp/intel-gtt.c
+++ b/drivers/char/agp/intel-gtt.c
@@ -812,8 +812,10 @@ static int intel_fake_agp_fetch_size(void)
 
 static void i830_cleanup(void)
 {
-       kunmap(intel_private.i8xx_page);
-       intel_private.i8xx_flush_page = NULL;
+       if (intel_private.i8xx_flush_page) {
+               kunmap(intel_private.i8xx_flush_page);
+               intel_private.i8xx_flush_page = NULL;
+       }
 
        __free_page(intel_private.i8xx_page);
        intel_private.i8xx_page = NULL;