On Thu, Apr 25, 2013 at 02:33:06PM +0800, Adam Lee wrote: > On Wed, Apr 24, 2013 at 11:17:52AM +0200, Laurent Pinchart wrote: > > Hi Adam, > > > > 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 > > > 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. > > > > 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. > > Here comes another one, integrated Chicony webcam 04f2:b39f, its > autosuspend makes `poweroff` performs rebooting at the laptop I'm > working on. I tried USB_QUIRK_RESET_RESUME, not helping. > > The quirks list will go longer and longer absolutely, do uvcvideo wanna > maintain that? And why only uvcvideo do this in kernel space which > against general USB module? > > I still suggest we disable it by default, people can enable it in udev > just like almost all distroes do for udisks. Please consider about it. Hi, Laurent Any comment of this? I still think it's a risk to enable autosuspend in uvcvideo by default, there must be users meeting weird issues but didn't report to you becaue they didn't figured out the cause. -- Regards, Adam Lee Hardware Enablement -- 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
