From: Takashi Iwai Date: Tue, 22 Jun 2021 17:00:49 +0000 (+0930) Subject: ALSA: usb-audio: scarlett2: Fix wrong resume call X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=785b6f29a795f109685f286b91e0250c206fbffb;p=linux.git ALSA: usb-audio: scarlett2: Fix wrong resume call The current way of the scarlett2 mixer code managing the usb_mixer_elem_info object is wrong in two ways: it passes its internal index to the head.id field, and the val_type field is uninitialized. This ended up with the wrong execution at the resume because a bogus unit id is passed wrongly. Also, in the later code extensions, we'll have more mixer elements, and passing the index will overflow the unit id size (of 256). This patch corrects those issues. It introduces a new value type, USB_MIXER_BESPOKEN, which indicates a non-standard mixer element, and use this type for all scarlett2 mixer elements, as well as initializing the fixed unit id 0 for avoiding the overflow. Tested-by: Geoffrey D. Bennett Signed-off-by: Geoffrey D. Bennett Cc: Link: https://lore.kernel.org/r/49721219f45b7e175e729b0d9d9c142fd8f4342a.1624379707.git.g@b4.vu Signed-off-by: Takashi Iwai --- diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 4ea4875abdf8f..30b3e128e28d8 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -3606,6 +3606,9 @@ static int restore_mixer_value(struct usb_mixer_elem_list *list) struct usb_mixer_elem_info *cval = mixer_elem_list_to_info(list); int c, err, idx; + if (cval->val_type == USB_MIXER_BESPOKEN) + return 0; + if (cval->cmask) { idx = 0; for (c = 0; c < MAX_CHANNELS; c++) { diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h index e5a01f17bf3c9..ea41e7a1f7bf2 100644 --- a/sound/usb/mixer.h +++ b/sound/usb/mixer.h @@ -55,6 +55,7 @@ enum { USB_MIXER_U16, USB_MIXER_S32, USB_MIXER_U32, + USB_MIXER_BESPOKEN, /* non-standard type */ }; typedef void (*usb_mixer_elem_dump_func_t)(struct snd_info_buffer *buffer, diff --git a/sound/usb/mixer_scarlett_gen2.c b/sound/usb/mixer_scarlett_gen2.c index dde008ea21d78..c4689c401d6e4 100644 --- a/sound/usb/mixer_scarlett_gen2.c +++ b/sound/usb/mixer_scarlett_gen2.c @@ -1136,10 +1136,15 @@ static int scarlett2_add_new_ctl(struct usb_mixer_interface *mixer, if (!elem) return -ENOMEM; + /* We set USB_MIXER_BESPOKEN type, so that the core USB mixer code + * ignores them for resume and other operations. + * Also, the head.id field is set to 0, as we don't use this field. + */ elem->head.mixer = mixer; elem->control = index; - elem->head.id = index; + elem->head.id = 0; elem->channels = channels; + elem->val_type = USB_MIXER_BESPOKEN; kctl = snd_ctl_new1(ncontrol, elem); if (!kctl) {