On Mon June 18 2012 14:19:51 Laurent Pinchart wrote: > Hi Hans, > > On Monday 18 June 2012 13:40:24 Hans Verkuil wrote: > > On Mon June 18 2012 12:01:47 Laurent Pinchart wrote: > > > On Sunday 10 June 2012 12:25:51 Hans Verkuil wrote: > > > > From: Hans Verkuil <hans.verkuil@xxxxxxxxx> > > > > > > > > Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > > > > --- > > > > > > > > drivers/media/video/v4l2-dev.c | 41 ++++++++++++++++++++++----------- > > > > 1 file changed, 29 insertions(+), 12 deletions(-) > > > > > > > > diff --git a/drivers/media/video/v4l2-dev.c > > > > b/drivers/media/video/v4l2-dev.c index 5c0bb18..54f387d 100644 > > > > --- a/drivers/media/video/v4l2-dev.c > > > > +++ b/drivers/media/video/v4l2-dev.c > > > > @@ -305,6 +305,9 @@ static ssize_t v4l2_read(struct file *filp, char > > > > __user > > > > *buf, ret = vdev->fops->read(filp, buf, sz, off); > > > > > > > > if (test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags)) > > > > > > > > mutex_unlock(vdev->lock); > > > > > > > > + if (vdev->debug) > > > > > > As vdev->debug is a bitmask, shouldn't we add an fops debug bit ? > > > > I actually want to move away from the bitmask idea. I've never really liked > > it here. > > Would using dev_dbg with dynamic printk instead of creating our own logging > system be an option ? I don't think so. There are lots of printk message you'd all have to enable. You just want to have a standard method of debugging which ioctls are called that anyone can use and that's consistent for all v4l drivers. This does just that. > > > > > + pr_info("%s: read: %zd (%d)\n", > > > > + video_device_node_name(vdev), sz, ret); > > > > > > Shouldn't we use KERN_DEBUG instead of KERN_INFO ? BTW, what about > > > replacing the pr_* calls with dev_* calls ? > > > > KERN_DEBUG vs KERN_INFO is actually a good question. My reasoning is that > > you explicitly enable logging, and so you really want to see it in the log, > > so we use KERN_INFO. With KERN_DEBUG you might have the situation where the > > debug level of the logging is disabled, so the messages are ignored. > > > > However, if people disagree with this, then I'm happy to move it back to > > KERN_DEBUG. > > On embedded systems KERN_INFO will be printed to the serial console. > Interleaving kernel messages with application output during capture result in > a mess. > > If someone enables debugging I expect him/her to know enough to get the kernel > log debug messages. OK, I'll change this back to KERN_DEBUG. Good argument. 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