From: Hans Verkuil <hans.verkuil@xxxxxxxxx> When compiling this for older kernels using the compatibility build the compiler complains about uninitialized variables: In file included from include/linux/kernel.h:20:0, from include/linux/cache.h:4, from include/linux/time.h:7, from include/linux/input.h:13, from /home/hans/work/build/media_build/v4l/compat.h:9, from <command-line>:0: /home/hans/work/build/media_build/v4l/videobuf2-core.c: In function 'vb2_mmap': include/linux/dynamic_debug.h:60:9: warning: 'plane' may be used uninitialized in this function [-Wmaybe-uninitialized] printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \ ^ /home/hans/work/build/media_build/v4l/videobuf2-core.c:2381:23: note: 'plane' was declared here unsigned int buffer, plane; ^ In file included from include/linux/kernel.h:20:0, from include/linux/cache.h:4, from include/linux/time.h:7, from include/linux/input.h:13, from /home/hans/work/build/media_build/v4l/compat.h:9, from <command-line>:0: include/linux/dynamic_debug.h:60:9: warning: 'buffer' may be used uninitialized in this function [-Wmaybe-uninitialized] printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \ ^ /home/hans/work/build/media_build/v4l/videobuf2-core.c:2381:15: note: 'buffer' was declared here unsigned int buffer, plane; ^ While these warnings are bogus (the call to __find_plane_by_offset will set buffer and plane), it doesn't hurt to initialize these variables. Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> --- drivers/media/v4l2-core/videobuf2-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index f8f694a..40024d7 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -2378,7 +2378,7 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) { unsigned long off = vma->vm_pgoff << PAGE_SHIFT; struct vb2_buffer *vb; - unsigned int buffer, plane; + unsigned int buffer = 0, plane = 0; int ret; unsigned long length; -- 1.9.2 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html