From: Mike Lockwood <lockwood@android.com>
Date: Fri, 16 Apr 2010 19:32:15 +0000 (-0400)
Subject: USB: composite: Add support for functions overriding USB_DT_STRING descriptors
X-Git-Tag: firefly_0821_release~7613^2~808
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=fb52b002c2d20205d01598f0440dc89ece98ba2d;p=firefly-linux-kernel-4.4.55.git

USB: composite: Add support for functions overriding USB_DT_STRING descriptors

Needed for MTP support.

Signed-off-by: Mike Lockwood <lockwood@android.com>
---

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index e15c0b6a5849..03b02876ba18 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -931,6 +931,21 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 		case USB_DT_STRING:
 			value = get_string(cdev, req->buf,
 					w_index, w_value & 0xff);
+
+			/* Allow functions to handle USB_DT_STRING.
+			 * This is required for MTP.
+			 */
+			if (value < 0) {
+				struct usb_configuration        *cfg;
+				list_for_each_entry(cfg, &cdev->configs, list) {
+					if (cfg && cfg->setup) {
+						value = cfg->setup(cfg, ctrl);
+						if (value >= 0)
+							break;
+					}
+				}
+			}
+
 			if (value >= 0)
 				value = min(w_length, (u16) value);
 			break;