Modern kernels enable dynamic printk support, which is fine, except when it is combined with a debug module option. Enabling debug in videobuf2-core now produces no debugging unless it is also enabled through the dynamic printk support in debugfs. Either use a debug module option + pr_info, or use pr_debug without a debug module option. In this case the fact that you can set various debug levels is very useful, so I believe that for videobuf2-core.c we should use pr_info. The mix of the two is very confusing: I've spent too much time already trying to figure out why I am not seeing any debug output in the kernel log when I do: echo 1 >/sys/modules/videobuf2_core/parameters/debug Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 0e3d927..0b59735 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -36,7 +36,7 @@ module_param(debug, int, 0644); #define dprintk(level, fmt, arg...) \ do { \ if (debug >= level) \ - pr_debug("vb2: %s: " fmt, __func__, ## arg); \ + pr_info("vb2: %s: " fmt, __func__, ## arg); \ } while (0) #ifdef CONFIG_VIDEO_ADV_DEBUG -- 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