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authorTakashi Iwai <tiwai@suse.de>2016-01-11 14:39:12 +0100
committerTakashi Iwai <tiwai@suse.de>2016-01-29 07:36:10 +0100
commite2703363316278cd4a8880671d38f783f7de18ba (patch)
tree84649bbdd9e0de9d853888cb464fcf6871b730ef /sound/usb/card.c
parent79289e24194a9d099bf18f200894832c5760cd83 (diff)
ALSA: usb-audio: Add quirk_alias option
This patch adds a new option "quirk_alias" to snd-usb-audio driver for allowing user to pass the quirk alias list. A quirk alias consists of a string form like 0123abcd:5678beef, which makes to apply a quirk to a device with USB ID 0123:abcd treated as if it were 5678:beef. This feature is useful to test an existing quirk, typically for a newer model of the same vendor, without patching / rebuilding the kernel driver. The current implementation is fairly simplistic: since there is no API for matching a usb_device_id to the given ID pair, it has an open code to loop over the id table and matches only with vendor:product pair. So far, this is OK, as all existing entries are with vendor:product pairs, indeed. Once when we have another matching entry, however, we'd need to update get_alias_quirk() as well. Note that this option is provided only for testing / development. If you want to have a proper support, contact to upstream for adding the matching quirk in the driver code statically. Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/card.c')
-rw-r--r--sound/usb/card.c47
1 files changed, 47 insertions, 0 deletions
diff --git a/sound/usb/card.c b/sound/usb/card.c
index 2c0269014b85..3fc63583a537 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -82,6 +82,7 @@ static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
static bool ignore_ctl_error;
static bool autoclock = true;
+static char *quirk_alias[SNDRV_CARDS];
module_param_array(index, int, NULL, 0444);
MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
@@ -100,6 +101,8 @@ MODULE_PARM_DESC(ignore_ctl_error,
"Ignore errors from USB controller for mixer interfaces.");
module_param(autoclock, bool, 0444);
MODULE_PARM_DESC(autoclock, "Enable auto-clock selection for UAC2 devices (default: yes).");
+module_param_array(quirk_alias, charp, NULL, 0444);
+MODULE_PARM_DESC(quirk_alias, "Quirk aliases, e.g. 0123abcd:5678beef.");
/*
* we keep the snd_usb_audio_t instances by ourselves for merging
@@ -457,6 +460,48 @@ static int snd_usb_audio_create(struct usb_interface *intf,
return 0;
}
+/* look for a matching quirk alias id */
+static bool get_alias_id(struct usb_device *dev, unsigned int *id)
+{
+ int i;
+ unsigned int src, dst;
+
+ for (i = 0; i < ARRAY_SIZE(quirk_alias); i++) {
+ if (!quirk_alias[i] ||
+ sscanf(quirk_alias[i], "%x:%x", &src, &dst) != 2 ||
+ src != *id)
+ continue;
+ dev_info(&dev->dev,
+ "device (%04x:%04x): applying quirk alias %04x:%04x\n",
+ USB_ID_VENDOR(*id), USB_ID_PRODUCT(*id),
+ USB_ID_VENDOR(dst), USB_ID_PRODUCT(dst));
+ *id = dst;
+ return true;
+ }
+
+ return false;
+}
+
+static struct usb_device_id usb_audio_ids[]; /* defined below */
+
+/* look for the corresponding quirk */
+static const struct snd_usb_audio_quirk *
+get_alias_quirk(struct usb_device *dev, unsigned int id)
+{
+ const struct usb_device_id *p;
+
+ for (p = usb_audio_ids; p->match_flags; p++) {
+ /* FIXME: this checks only vendor:product pair in the list */
+ if ((p->match_flags & USB_DEVICE_ID_MATCH_DEVICE) ==
+ USB_DEVICE_ID_MATCH_DEVICE &&
+ p->idVendor == USB_ID_VENDOR(id) &&
+ p->idProduct == USB_ID_PRODUCT(id))
+ return (const struct snd_usb_audio_quirk *)p->driver_info;
+ }
+
+ return NULL;
+}
+
/*
* probe the active usb device
*
@@ -483,6 +528,8 @@ static int usb_audio_probe(struct usb_interface *intf,
ifnum = get_iface_desc(alts)->bInterfaceNumber;
id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
le16_to_cpu(dev->descriptor.idProduct));
+ if (get_alias_id(dev, &id))
+ quirk = get_alias_quirk(dev, id);
if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
return -ENXIO;