Hi Jacek, On Thu, Dec 08, 2016 at 11:04:20PM +0100, Jacek Anaszewski wrote: > Hi Sakari, > > On 11/24/2016 01:17 PM, Sakari Ailus wrote: > >Hi Jacek, > > > >Thanks for the patchset. > > > >On Wed, Oct 12, 2016 at 04:35:19PM +0200, Jacek Anaszewski wrote: > >>Add helper functions that allow for easy instantiation of media_device > >>object basing on whether the media device contains v4l2 subdev with > >>given file descriptor. > > > >Doesn't this work with video nodes as well? That's what you seem to be using > >it for later on. And I think that's actually more useful. > > > >The existing implementation uses udev to look up devices. Could you use > >libudev device enumeration API to find the media devices, and fall back to > >sysfs if udev doesn't work? There seems to be a reasonable-looking example > >here: > > > ><URL:http://stackoverflow.com/questions/25361042/how-to-list-usb-mass-storage-devices-programatically-using-libudev-in-linux> > > Actually I am calling media_get_devname_udev() at first and falling back > to sysfs similarly as it is accomplished in media_enum_entities(). > Is there any specific reason for which I should use libudev device > enumeration API in media_device_new_by_subdev_fd()?
Yes. You rely on the API udev provides; the sysfs implementation is just a fallback in case udev isn't available in the system. I guess it'd mostly work but, for instance, you assume sysfs is found under /sys. The sysfs itself isn't one of the most stable APIs either. Udev is a simply better option when it's there. -- Kind regards, Sakari Ailus e-mail: sakari.ai...@iki.fi XMPP: sai...@retiisi.org.uk -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
