On Thu, Nov 17, 2011 at 11:07:16AM +0100, Jean-Francois Moine wrote: > On Wed, 16 Nov 2011 15:19:04 -0300 > Ezequiel Garc??a <elezegarcia@xxxxxxxxx> wrote: > > > In 'media/video/gspca/gspca.c' I really hated this cast (maybe because > > I am too dumb to understand it): > > > > gspca_dev = (struct gspca_dev *) video_devdata(file); > > > > wich is only legal because a struct video_device is the first member > > of gspca_dev. IMHO, this is 'unnecesary obfuscation'. > > The thing is the driver is surely working fine and there is no good > > reasong for the change. > > > > Is it ok to submit a patchset to change this? Something like this: > > > > diff --git a/drivers/media/video/gspca/gspca.c > > b/drivers/media/video/gspca/gspca.c > > index 881e04c..5d962ce 100644 > > --- a/drivers/media/video/gspca/gspca.c > > +++ b/drivers/media/video/gspca/gspca.c > > @@ -1304,9 +1306,11 @@ static void gspca_release(struct video_device *vfd) > > static int dev_open(struct file *file) > > { > > struct gspca_dev *gspca_dev; > > + struct video_device *vdev; > > > > PDEBUG(D_STREAM, "[%s] open", current->comm); > > - gspca_dev = (struct gspca_dev *) video_devdata(file); > > + vdev = video_devdata(file); > > + gspca_dev = video_get_drvdata(vdev); > > if (!gspca_dev->present) > > Hi Ezequiel, > > You are right, the cast is not a good way (and there are a lot of them > in the gspca subdrivers), but your patch does not work because the > 'private_data' of the device is not initialized (there is no call to > video_set_drvdata). > > So, a possible cleanup could be: > > > - gspca_dev = (struct gspca_dev *) video_devdata(file); > > + gspca_dev = container_of(video_devdata(file), struct gspca_dev, vdev); > > Is it OK for you? > Hi Jef, I just sent a patch to linux-media for this little issue. I realize it is only a very minor patch, so I am not sure If I am helping or just annoying the developers ;) Anyway, if you could check the patch I would appreciate it. A few questions arose: * I made the patch on this tree: git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media not sure if this is ok. * Should I send gspca's patches to anyone else besides you and the list? * I have this on my MAINTANIERS file: git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6.git But that repo seems no longer alive, maybe MAINTAINERS need some updating. Again, hope the patch helps, Thanks, Ezequiel. -- 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