Hmm, interesting. Twice 'sparse' in the same subject line with different meanings :-) This is another sparse error I get with drivers/media/v4l2-core/v4l2-ioctl.c: drivers/media/v4l2-core/v4l2-ioctl.c:424:9: error: cannot size expression (there are more of those in drivers/media, all with the same cause). This sparse (the tool) error occurs because of sparse (C language) array initialization in combination with ARRAY_SIZE: static const char *v4l2_memory_names[] = { [V4L2_MEMORY_MMAP] = "mmap", [V4L2_MEMORY_USERPTR] = "userptr", [V4L2_MEMORY_OVERLAY] = "overlay", [V4L2_MEMORY_DMABUF] = "dmabuf", }; #define prt_names(a, arr) (((unsigned)(a)) < ARRAY_SIZE(arr) ? arr[a] : "unknown") static void v4l_print_requestbuffers(const void *arg, bool write_only) { const struct v4l2_requestbuffers *p = arg; pr_cont("count=%d, type=%s, memory=%s\n", p->count, prt_names(p->type, v4l2_type_names), prt_names(p->memory, v4l2_memory_names)); } I could change v4l2_memory_names to: static const char *v4l2_memory_names[V4L2_MEMORY_DMABUF + 1] = { and the error goes away. I'm actually not sure if this is a sparse bug or a feature. If it is a feature then the error message is definitely wrong, since the size is perfectly well defined. As an aside: the error message is pretty vague IMHO. Regards, Hans -- 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