Hello all, While debugging one of my apps I noticed that the saa7134 driver makes the VBI device readable in select() and returns EIO for ioctl DQBUF when there's no signal, i.e. when the card appearently doesn't generate an interrupt for a long time. Not sure what this is meant to be used for since users can implement a timeout if needed with select(), but anyways, the matter I'm worrying about is that DQBUF in this case does not simply abort, but actually does de-queue a buffer although it returns an error code. Is this a bug or a feature? If it's a feature I don't understand how the user is supposed to deal with it, since video_usercopy() sees the error code returned by the ioctl and hence does not copy struct v4l2_buffer into user space, so the user doesn't even obtain the buffer index and cannot re-queue it. Hence EIO turns into EINVAL after a few iterations, i.e. when all buffers are exhausted, and most apps will either abort or busy loop since select() doesn't block anymore. In any case the EIO error code should be documented in the v4l2 API specification, currently at http://bytesex.org/v4l/spec/r7556.html bye, -tom
