Re: [PATCH] Revert "V4L/DVB: uvc: Enable USB autosuspend by default on uvcvideo"
From: Laurent Pinchart
Date: Wed Apr 24 2013 - 05:18:00 EST
Thanks for the patch.
On Wednesday 24 April 2013 15:57:19 adam.lee@xxxxxxxxxxxxx wrote:
> From: Adam Lee <adam.lee@xxxxxxxxxxxxx>
> This reverts commit 3dae8b41dc5651f8eb22cf310e8b116480ba25b7.
> 1, I do have a Chicony webcam, implements autosuspend in a broken way,
> make `poweroff` performs rebooting when its autosuspend enabled.
> 2, There are other webcams which don't support autosuspend too, like
> 3, kernel removed USB_QUIRK_NO_AUTOSUSPEND in
> a691efa9888e71232dfb4088fb8a8304ffc7b0f9, because autosuspend is
> disabled by default.
> So, we need to disable autosuspend in uvcvideo, maintaining a quirk list
> only for uvcvideo is not a good idea.
> Signed-off-by: Adam Lee <adam.lee@xxxxxxxxxxxxx>
I've received very few bug reports about broken auto-suspend support in UVC
devices. Most of them could be solved by setting the RESET_RESUME quirk in USB
core, only the Creative Live! Cam Optia AF required a quirk in the uvcvideo
driver. I would thus rather use the available quirks (USB_QUIRK_RESET_RESUME
if possible, UVC_QUIRK_DISABLE_AUTOSUSPEND otherwise) than killing power
management for the vast majority of webcams that behave correctly.
> drivers/media/usb/uvc/uvc_driver.c | 1 -
> 1 file changed, 1 deletion(-)
> diff --git a/drivers/media/usb/uvc/uvc_driver.c
> b/drivers/media/usb/uvc/uvc_driver.c index 5dbefa6..8556f7c 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -1914,7 +1914,6 @@ static int uvc_probe(struct usb_interface *intf,
> uvc_trace(UVC_TRACE_PROBE, "UVC device initialized.\n");
> - usb_enable_autosuspend(udev);
> return 0;
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