On Sat, Jun 11, 2011 at 1:02 PM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote: > OK, but how do you get it into standby in the first place? (I must be missing > something here...) The tuner core puts the chip into standby when the last V4L filehandle is closed. Yes, I realize this violates the V4L spec since you should be able to make multiple calls with something like v4l2-ctl, but nobody has ever come up with a better mechanism for knowing when to put the device to sleep. We've been forced to choose between the purist perspective, which is properly preserving state, never powering down the tuner and sucking up 500ma on the USB port when not using the tuner, versus powering down the tuner when the last party closes the filehandle, which preserves power but breaks v4l2 conformance and in some cases is highly noticeable with tuners that require firmware to be reloaded when being powered back up. Devin -- Devin J. Heitmueller - Kernel Labs http://www.kernellabs.com -- 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
