gfx: drv: Warn if mode_config.mutex is not locked in GTT code

The GTT ref counting relies on mode_config.mutex for protection. Print a
warning if the code is called without holding the mutex.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

diff --git a/drivers/staging/mrst/drv/psb_gtt.c b/drivers/staging/mrst/drv/psb_gtt.c
index 9610f7a..2025c9e 100644 (file)
--- a/drivers/staging/mrst/drv/psb_gtt.c
+++ b/drivers/staging/mrst/drv/psb_gtt.c
@@ -897,6 +897,8 @@ int psb_gtt_map_meminfo(struct drm_device *dev,
 {
        struct psb_gtt_mem_mapping *mapping;
 
+       WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
+
        /* check if memory is already mapped */
        mapping = psb_gtt_find_mapping_for_key(dev, psb_get_tgid(),
                                               (u32) psKernelMemInfo);
@@ -940,6 +942,8 @@ int psb_gtt_unmap_meminfo(struct drm_device *dev,
 {
        struct psb_gtt_mem_mapping *mapping;
 
+       WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
+
        mapping = psb_gtt_find_mapping_for_key(dev, tgid,
                                               (u32) psKernelMemInfo);
        if (IS_ERR(mapping)) {