Re: [PATCH] video4linux: Push down the BKL

From: Hans Verkuil
Date: Fri May 23 2008 - 02:30:09 EST

On Friday 23 May 2008 08:16:05 Hans Verkuil wrote:
> On Friday 23 May 2008 04:08:04 Andy Walls wrote:
> > On Thu, 2008-05-22 at 22:37 +0100, Alan Cox wrote:
> > > For most drivers the generic ioctl handler does the work and we
> > > update it and it becomes the unlocked_ioctl method. Older drivers
> > > use the usercopy method so we make it do the work. Finally there
> > > are a few special cases.
> > >
> > > Signed-off-by: Alan Cox <alan@xxxxxxxxxx>
> >
> > I'd like to start planning out the changes to eliminate the BKL
> > from cx18.
> >
> > Could someone give me a brief education as to what elements of
> > cx18/ivtv_v4l2_do_ioctl() would be forcing the use of the BKL for
> > these drivers' ioctls? I'm assuming it's not the
> > mutex_un/lock(&....->serialize_lock) and that the answer's not in
> > the diff.
> To the best of my knowledge there is no need for a BKL in ivtv or
> cx18. It was just laziness on my part that I hadn't switched to
> unlocked_ioctl yet. If you know of a reason why it should be kept for
> now, then I'd like to know, otherwise the BKL can be removed
> altogether for ivtv/cx18. I suspect you just pushed the lock down
> into the driver and in that case you can just remove it for
> ivtv/cx18.

Hmm, of course you just pushed down the lock, the subject said so.
Sorry, it's early morning here and I'm apparently not yet fully
awake :-)


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at