On Fri, 11 Oct 2013 14:40:32 +0200 Paul Chavent <paul.chav...@onera.fr> wrote:
> The PPS_FETCH ioctl is blocking still the reception of a PPS > event. But, in some case, one may immediately need the last event > date. This patch allow to get the result of PPS_FETCH if the device > has the O_NONBLOCK flag set. Are the PPS ioctls actually documented anywhere? Documentation/pps/pps.txt is silent. That's a shame, because it would be nice to have a formal description of the the PPS_FETCH semantics which leads to an understanding of why things are the way they are, how PPS_FETCH is supposed to be used, etc. Also, the presence of such documentation would permit me to bug you for not having updated it! We need *some* channel for telling people about the driver, and updates to it. Maybe linuxpps.org has it somewhere, but I couldn't immediately find it. Your implementation requires that the file be opened non-blocking. But I'd have thought that adding a new and separate ioctl mode would be a cleaner and more flexible implementation - that way an app which wants both blocking and non-blocking behaviour doesn't need to open the file twice. Also, this is actually a non-backward-compatible change for any application which happened to be opening the file with O_NONBLOCK! Hopefully there aren't any such applications... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
