Re: [PATCH 3/3] [media] au0828-video: Move two assignments in au0828_init_isoc()

[Hans Verkuil]

On 03/11/16 20:56, SF Markus Elfring wrote:
> > > From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> > > Date: Mon, 24 Oct 2016 22:44:02 +0200
> > >
> > > Move the assignment for the data structure members "isoc_copy"
> > > and "num_bufs" behind the source code for memory allocations
> > > by this function.
> >
> > I don't see the point,
>
> Another explanation try â
>
>
> > dropping this patch.
>
> I proposed that these assignments should only be performed after the required
> memory allocations succeeded. Is this detail worth for further considerations?

I understand why you think it is better, but I disagree :-) I prefer the 
current
approach, that way I know as a reviewer that these fields are correctly 
set and
I can forget about them. Not worth spending more time on this.

Regards,

	Hans

> > > Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> > > ---
> > >  drivers/media/usb/au0828/au0828-video.c | 5 ++---
> > >  1 file changed, 2 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/media/usb/au0828/au0828-video.c b/drivers/media/usb/au0828/au0828-video.c
> > > index b5c88a7..5ebda64 100644
> > > --- a/drivers/media/usb/au0828/au0828-video.c
> > > +++ b/drivers/media/usb/au0828/au0828-video.c
> > > @@ -218,9 +218,6 @@ static int au0828_init_isoc(struct au0828_dev *dev, int max_packets,
> > >      int rc;
> > >
> > >      au0828_isocdbg("au0828: called au0828_prepare_isoc\n");
> > > -
> > > -    dev->isoc_ctl.isoc_copy = isoc_copy;
> > > -    dev->isoc_ctl.num_bufs = num_bufs;
> > >      dev->isoc_ctl.urb = kcalloc(num_bufs,
> > >                      sizeof(*dev->isoc_ctl.urb),
> > >                      GFP_KERNEL);
> > > @@ -240,6 +237,7 @@ static int au0828_init_isoc(struct au0828_dev *dev, int max_packets,
> > >      dev->isoc_ctl.buf = NULL;
> > >
> > >      sb_size = max_packets * dev->isoc_ctl.max_pkt_size;
> > > +    dev->isoc_ctl.num_bufs = num_bufs;
> > >
> > >      /* allocate urbs and transfer buffers */
> > >      for (i = 0; i < dev->isoc_ctl.num_bufs; i++) {
> > > @@ -276,6 +274,7 @@ static int au0828_init_isoc(struct au0828_dev *dev, int max_packets,
> > >              k += dev->isoc_ctl.max_pkt_size;
> > >          }
> > >      }
> > > +    dev->isoc_ctl.isoc_copy = isoc_copy;
> > >
> > >      /* submit urbs and enables IRQ */
> > >      for (i = 0; i < dev->isoc_ctl.num_bufs; i++) {