drm: make drm_get_format_name thread-safe
Signed-off-by: Eric Engestrom <eric@engestrom.ch>
[danvet: Clarify that the returned pointer must be freed with
kfree().]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index 0645c85..d8f65c4 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -39,16 +39,14 @@
* drm_get_format_name - return a string for drm fourcc format
* @format: format to compute name of
*
- * Note that the buffer used by this function is globally shared and owned by
- * the function itself.
- *
- * FIXME: This isn't really multithreading safe.
+ * Note that the buffer returned by this function is owned by the caller
+ * and will need to be freed using kfree().
*/
const char *drm_get_format_name(uint32_t format)
{
- static char buf[32];
+ char *buf = kmalloc(32, GFP_KERNEL);
- snprintf(buf, sizeof(buf),
+ snprintf(buf, 32,
"%c%c%c%c %s-endian (0x%08x)",
printable_char(format & 0xff),
printable_char((format >> 8) & 0xff),
@@ -73,6 +71,8 @@
void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
int *bpp)
{
+ const char *format_name;
+
switch (format) {
case DRM_FORMAT_C8:
case DRM_FORMAT_RGB332:
@@ -127,8 +127,9 @@
*bpp = 32;
break;
default:
- DRM_DEBUG_KMS("unsupported pixel format %s\n",
- drm_get_format_name(format));
+ format_name = drm_get_format_name(format);
+ DRM_DEBUG_KMS("unsupported pixel format %s\n", format_name);
+ kfree(format_name);
*depth = 0;
*bpp = 0;
break;