From cea2dbec1b8e84b95459f4a589c613b84e3d9737 Mon Sep 17 00:00:00 2001 From: Jonathan Bell Date: Wed, 15 Sep 2021 17:56:45 +0100 Subject: [PATCH] sound/usb: call usb_autopm_get_interface() for devices that should not be suspended Webcams with microphones are composite devices, and autosuspend is set at the device level. If uvcvideo is probed after snd-usb-audio, the effect of the quirk applied by snd-usb-audio is undone by uvcvideo's global application of autosuspend. Incrementing the interface's PM refcount in such cases prevents runtime PM from happening, thus the device is left active. Signed-off-by: Jonathan Bell --- sound/usb/card.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -825,8 +825,14 @@ static int usb_audio_probe(struct usb_in if (ignore_ctl_error) chip->quirk_flags |= QUIRK_FLAG_IGNORE_CTL_ERROR; - if (chip->quirk_flags & QUIRK_FLAG_DISABLE_AUTOSUSPEND) + if (chip->quirk_flags & QUIRK_FLAG_DISABLE_AUTOSUSPEND) { + /* + * Grab the interface, because on a webcam uvcvideo may race + * with snd-usb-audio during probe and re-enable autosuspend. + */ + usb_autopm_get_interface(intf); usb_disable_autosuspend(interface_to_usbdev(intf)); + } /* * For devices with more than one control interface, we assume the