From 9d4ae593fc578f6c88ce48a8b974e306de159e99 Mon Sep 17 00:00:00 2001 From: Will Porter Date: Thu, 27 Aug 2026 18:21:42 -0500 Subject: [PATCH] ALSA: usb-audio: Add PM guards to RME Digiface controls The RME Digiface status and register helpers issue vendor requests without preventing runtime suspend or disconnect. The volatile status controls can repeatedly reach these unguarded paths while userspace polls them. Protect both helpers with snd_usb_lock. All Digiface get and put callbacks then resume the device and hold the disconnect reference across their transfer. Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Will Porter Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20260827232143.149197-6-mrwillporter@gmail.com --- sound/usb/mixer_quirks.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c index a1f5592cc5d5..fc622eb95dc5 100644 --- a/sound/usb/mixer_quirks.c +++ b/sound/usb/mixer_quirks.c @@ -3480,6 +3480,10 @@ static int snd_rme_digiface_write_reg(struct snd_kcontrol *kcontrol, int item, u struct usb_device *dev = chip->dev; int err; + CLASS(snd_usb_lock, pm)(chip); + if (pm.err < 0) + return -EIO; + err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), item, USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE, @@ -3499,6 +3503,10 @@ static int snd_rme_digiface_read_status(struct snd_kcontrol *kcontrol, u32 statu __le32 buf[4] = {}; int err; + CLASS(snd_usb_lock, pm)(chip); + if (pm.err < 0) + return -EIO; + err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), RME_DIGIFACE_READ_STATUS, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,