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-rw-r--r--drivers/usb/core/generic.c44
1 files changed, 25 insertions, 19 deletions
diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
index f713cecc1f41..1ac9c1e5f773 100644
--- a/drivers/usb/core/generic.c
+++ b/drivers/usb/core/generic.c
@@ -118,6 +118,31 @@ int usb_choose_configuration(struct usb_device *udev)
continue;
}
+ /*
+ * Select first configuration as default for audio so that
+ * devices that don't comply with UAC3 protocol are supported.
+ * But, still iterate through other configurations and
+ * select UAC3 compliant config if present.
+ */
+ if (desc && is_audio(desc)) {
+ /* Always prefer the first found UAC3 config */
+ if (is_uac3_config(desc)) {
+ best = c;
+ break;
+ }
+
+ /* If there is no UAC3 config, prefer the first config */
+ else if (i == 0)
+ best = c;
+
+ /* Unconditional continue, because the rest of the code
+ * in the loop is irrelevant for audio devices, and
+ * because it can reassign best, which for audio devices
+ * we don't want.
+ */
+ continue;
+ }
+
/* When the first config's first interface is one of Microsoft's
* pet nonstandard Ethernet-over-USB protocols, ignore it unless
* this kernel has enabled the necessary host side driver.
@@ -132,25 +157,6 @@ int usb_choose_configuration(struct usb_device *udev)
#endif
}
- /*
- * Select first configuration as default for audio so that
- * devices that don't comply with UAC3 protocol are supported.
- * But, still iterate through other configurations and
- * select UAC3 compliant config if present.
- */
- if (i == 0 && num_configs > 1 && desc && is_audio(desc)) {
- best = c;
- continue;
- }
-
- if (i > 0 && desc && is_audio(desc)) {
- if (is_uac3_config(desc)) {
- best = c;
- break;
- }
- continue;
- }
-
/* From the remaining configs, choose the first one whose
* first interface is for a non-vendor-specific class.
* Reason: Linux is more likely to have a class driver