drm/radeon: only add the mm i2c bus if the hw_i2c module param is set
authorAlex Deucher <alexander.deucher@amd.com>
Tue, 10 Apr 2012 16:14:27 +0000 (12:14 -0400)
committerDave Airlie <airlied@redhat.com>
Wed, 11 Apr 2012 08:36:53 +0000 (09:36 +0100)
It seems it can corrupt the monitor EDID in certain cases on certain
boards when running sensors detect.  It's rarely used anyway outside
of AIW boards.

http://lists.lm-sensors.org/pipermail/lm-sensors/2012-April/035847.html
http://lists.freedesktop.org/archives/xorg/2011-January/052239.html

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
drivers/gpu/drm/radeon/radeon_i2c.c

index 85bcfc8..3edec1c 100644 (file)
@@ -900,6 +900,10 @@ struct radeon_i2c_chan *radeon_i2c_create(struct drm_device *dev,
        struct radeon_i2c_chan *i2c;
        int ret;
 
+       /* don't add the mm_i2c bus unless hw_i2c is enabled */
+       if (rec->mm_i2c && (radeon_hw_i2c == 0))
+               return NULL;
+
        i2c = kzalloc(sizeof(struct radeon_i2c_chan), GFP_KERNEL);
        if (i2c == NULL)
                return NULL;