[PATCH] usb: Ignore endpoints in non-zero altsettings

[Hector Martin]

We currently do not really handle altsettings properly, and no driver
uses them. Ignore the respective endpoint descriptors for secondary
altsettings, to avoid creating duplicate endpoint records in the
interface.

This will have to be revisited if/when we have a driver that needs
altsettings to work properly.

Signed-off-by: Hector Martin <marcan at marcan.st>
---
 common/usb.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/common/usb.c b/common/usb.c
index aad13fd9c557..90f72fda00bc 100644
--- a/common/usb.c
+++ b/common/usb.c
@@ -463,6 +463,15 @@ static int usb_parse_config(struct usb_device *dev,
 				puts("Endpoint descriptor out of order!\n");
 				break;
 			}
+			if (if_desc->num_altsetting > 1) {
+				/*
+				 * Ignore altsettings, which can trigger duplicate
+				 * endpoint errors below. Revisit this when some
+				 * driver actually needs altsettings with differing
+				 * endpoint setups.
+				 */
+				break;
+			}
 			epno = dev->config.if_desc[ifno].no_of_ep;
 			if_desc = &dev->config.if_desc[ifno];
 			if (epno >= USB_MAXENDPOINTS) {

---
base-commit: 8ad1c9c26f7740806a162818b790d4a72f515b7e
change-id: 20231029-usb-fixes-4-ba6931acf217

Best regards,
-- 
Hector Martin <marcan at marcan.st>