From: Mike Lockwood <lockwood@android.com>
Date: Sun, 13 Mar 2011 00:59:12 +0000 (-0500)
Subject: USB: gadget: f_accessory: Clear previous strings on ACCESSORY_GET_PROTOCOL
X-Git-Tag: firefly_0821_release~9834^2~52
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=30e18b848c25d4a90e3b6282cd32e19a2f0cd4dc;p=firefly-linux-kernel-4.4.55.git

USB: gadget: f_accessory: Clear previous strings on ACCESSORY_GET_PROTOCOL

Clearing strings on disconnect does not work since we may receive
a disconnect on some devices when transitioning into accessory mode.
We require an accessory to send ACCESSORY_GET_PROTOCOL before
sending any strings, so any strings from a previous session will be cleared.

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

diff --git a/drivers/usb/gadget/f_accessory.c b/drivers/usb/gadget/f_accessory.c
index ef21c05caaed..f6a5922e8c3b 100644
--- a/drivers/usb/gadget/f_accessory.c
+++ b/drivers/usb/gadget/f_accessory.c
@@ -220,13 +220,6 @@ static void acc_set_disconnected(struct acc_dev *dev)
 {
 	dev->online = 0;
 	dev->disconnected = 1;
-
-	/* clear all accessory strings */
-	memset(dev->manufacturer, 0, sizeof(dev->manufacturer));
-	memset(dev->model, 0, sizeof(dev->model));
-	memset(dev->description, 0, sizeof(dev->description));
-	memset(dev->version, 0, sizeof(dev->version));
-	memset(dev->uri, 0, sizeof(dev->uri));
 }
 
 static void acc_complete_in(struct usb_ep *ep, struct usb_request *req)
@@ -657,6 +650,13 @@ static int acc_function_setup(struct usb_function *f,
 			if (b_request == ACCESSORY_GET_PROTOCOL) {
 				*((u16 *)cdev->req->buf) = PROTOCOL_VERSION;
 				value = sizeof(u16);
+
+				/* clear any strings left over from a previous session */
+				memset(dev->manufacturer, 0, sizeof(dev->manufacturer));
+				memset(dev->model, 0, sizeof(dev->model));
+				memset(dev->description, 0, sizeof(dev->description));
+				memset(dev->version, 0, sizeof(dev->version));
+				memset(dev->uri, 0, sizeof(dev->uri));
 			}
 		}
 	}