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ALSA: usb-audio: Support string-descriptor-based quirk table entry

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Some quirky devices do not have a unique VID/PID. Matching them using
DEVICE_FLG() or VENDOR_FLG() may result in conflicts.

Add two new macros DEVICE_STRING_FLG() and VENDOR_STRING_FLG() to match
USB string descriptors (manufacturer and/or product) in addition to VID
and/or PID, so that we can deconflict these devices safely.

No functional change intended.

Signed-off-by: Rong Zhang <i@rong.moe>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260303194805.266158-5-i@rong.moe
This commit is contained in:
Rong Zhang 2026-03-04 03:47:59 +08:00 committed by Takashi Iwai
parent 52dc4b190a
commit 30f68d090c
1 changed files with 78 additions and 0 deletions
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78
sound/usb/quirks.c
View File

@ -2,8 +2,11 @@
/*
*/
#include <linux/cleanup.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/usb.h>
#include <linux/usb/audio.h>
#include <linux/usb/midi.h>
@ -2135,16 +2138,39 @@ void snd_usb_audioformat_attributes_quirk(struct snd_usb_audio *chip,
/*
* driver behavior quirk flags
*/
struct usb_string_match {
const char *manufacturer;
const char *product;
};
struct usb_audio_quirk_flags_table {
u32 id;
u32 flags;
const struct usb_string_match *usb_string_match;
};
#define DEVICE_FLG(vid, pid, _flags) \
{ .id = USB_ID(vid, pid), .flags = (_flags) }
#define VENDOR_FLG(vid, _flags) DEVICE_FLG(vid, 0, _flags)
/* Use as a last resort if using DEVICE_FLG() is prone to VID/PID conflicts. */
#define DEVICE_STRING_FLG(vid, pid, _manufacturer, _product, _flags) \
{ \
.id = USB_ID(vid, pid), \
.usb_string_match = &(const struct usb_string_match) { \
.manufacturer = _manufacturer, \
.product = _product, \
}, \
.flags = (_flags), \
}
/* Use as a last resort if using VENDOR_FLG() is prone to VID conflicts. */
#define VENDOR_STRING_FLG(vid, _manufacturer, _flags) \
DEVICE_STRING_FLG(vid, 0, _manufacturer, NULL, _flags)
static const struct usb_audio_quirk_flags_table quirk_flags_table[] = {
/* Device and string descriptor matches */
/* Device matches */
DEVICE_FLG(0x001f, 0x0b21, /* AB13X USB Audio */
QUIRK_FLAG_FORCE_IFACE_RESET | QUIRK_FLAG_IFACE_DELAY),
@ -2416,6 +2442,8 @@ static const struct usb_audio_quirk_flags_table quirk_flags_table[] = {
DEVICE_FLG(0x534d, 0x2109, /* MacroSilicon MS2109 */
QUIRK_FLAG_ALIGN_TRANSFER),
/* Vendor and string descriptor matches */
/* Vendor matches */
VENDOR_FLG(0x045e, /* MS Lifecam */
QUIRK_FLAG_GET_SAMPLE_RATE),
@ -2560,14 +2588,64 @@ void snd_usb_apply_flag_dbg(const char *reason,
}
}
#define USB_STRING_SIZE 128
static char *snd_usb_get_string(struct snd_usb_audio *chip, int id)
{
char *buf;
int ret;
/*
* Devices without the corresponding string descriptor.
* This is non-fatal as *_STRING_FLG have nothing to do in this case.
*/
if (id == 0)
return ERR_PTR(-ENODATA);
buf = kmalloc(USB_STRING_SIZE, GFP_KERNEL);
if (buf == NULL)
return ERR_PTR(-ENOMEM);
ret = usb_string(chip->dev, id, buf, USB_STRING_SIZE);
if (ret < 0) {
usb_audio_warn(chip, "failed to get string for id%d: %d\n", id, ret);
kfree(buf);
return ERR_PTR(ret);
}
return buf;
}
void snd_usb_init_quirk_flags_table(struct snd_usb_audio *chip)
{
const struct usb_audio_quirk_flags_table *p;
char *manufacturer __free(kfree) = NULL;
char *product __free(kfree) = NULL;
for (p = quirk_flags_table; p->id; p++) {
if (chip->usb_id == p->id ||
(!USB_ID_PRODUCT(p->id) &&
USB_ID_VENDOR(chip->usb_id) == USB_ID_VENDOR(p->id))) {
/* Handle DEVICE_STRING_FLG/VENDOR_STRING_FLG. */
if (p->usb_string_match && p->usb_string_match->manufacturer) {
if (!manufacturer) {
manufacturer = snd_usb_get_string(chip,
chip->dev->descriptor.iManufacturer);
}
if (IS_ERR_OR_NULL(manufacturer) ||
strcmp(p->usb_string_match->manufacturer, manufacturer))
continue;
}
if (p->usb_string_match && p->usb_string_match->product) {
if (!product) {
product = snd_usb_get_string(chip,
chip->dev->descriptor.iProduct);
}
if (IS_ERR_OR_NULL(product) ||
strcmp(p->usb_string_match->product, product))
continue;
}
snd_usb_apply_flag_dbg("builtin table", chip, p->flags);
chip->quirk_flags |= p->flags;
return;