Messages in this thread | | | From | Laurent Pinchart <> | Subject | Re: [PATCH] Revert "V4L/DVB: uvc: Enable USB autosuspend by default on uvcvideo" | Date | Wed, 24 Apr 2013 11:17:52 +0200 |
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Hi Adam,
Thanks for the patch.
On Wednesday 24 April 2013 15:57:19 adam.lee@canonical.com wrote: > From: Adam Lee <adam.lee@canonical.com> > > 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 > https://patchwork.kernel.org/patch/2356141/ > > 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@canonical.com>
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; > > error:
-- Regards,
Laurent Pinchart
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