Re: [PATCH/RFC] videodev.[ch] redesign

Gerd Knorr
2002-02-09T22:00:15Z

> > It also provides a ioctl wrapper function which handles copying the
> > ioctl args from/to userspace, so we have this at one place can drop all
> > the copy_from/to_user calls within the v4l device driver ioctl handlers.
>
> That is a large improvement.
> But you don't include a lock against reentry, which is bad.

I don't want to handle the wrapper function too much. IMHO it is the
job of the driver to do locking if needed. For some read-only ioctls
like VIDIOCGCAP you don't need locking at all.

> > Comments?
>
> Could you make a helper for open like for ioctl ?

video_open does call video_device[minor]->fops->open(), isn't that
enought?

> And please don't use a pointer to the device descriptor
> in the file structure. It makes live for USB devices much harder.

Sorry, I don't understand. What exactly do you mean?
file->private_data? videodev.c doesn't touch it ...

Gerd

--
#define ENOCLUE 125 /* userland programmer induced race condition */