commit 43b9f32d20a41d108d936b776ddfec9d47ad364a
author Nico Huber <nico.huber@secunet.com> Mon May 21 14:05:41 2012 +0200
committer Peter Stuge <peter@stuge.se> Wed Jun 20 19:47:07 2012 +0200
tree 0e7cf8ae198b30e21b3dc98e50845b2610f71e60
parent 421303a25aef04bb3d5431a4e6f4f6215bc772fe

libpayload: Better error detection in USB mass storage

This implements status transport (CSW) more closely to the standard
(usbmassbulk_10).

Change-Id: Ife516316e054d4e87ebe698dc487eeb9ebcfd38d
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/1072
Reviewed-by: Peter Stuge <peter@stuge.se>
Tested-by: build bot (Jenkins)

payloads/libpayload/drivers/usb/usbmsc.c

diff --git a/payloads/libpayload/drivers/usb/usbmsc.c b/payloads/libpayload/drivers/usb/usbmsc.c
index 8d57736..fd6517a 100644
--- a/payloads/libpayload/drivers/usb/usbmsc.c
+++ b/payloads/libpayload/drivers/usb/usbmsc.c
@@ -151,8 +151,8 @@
 	return luns;
 }
 
-int tag;
-int lun = 0;
+unsigned int tag;
+unsigned char lun = 0;
 
 static void
 wrap_cbw (cbw_t *cbw, int datalen, cbw_direction dir, const u8 *cmd,
@@ -161,7 +161,7 @@
 	memset (cbw, 0, sizeof (cbw_t));
 
 	cbw->dCBWSignature = cbw_signature;
-	cbw->dCBWTag = tag++;
+	cbw->dCBWTag = ++tag;
 	cbw->bCBWLUN = lun;	// static value per device
 
 	cbw->dCBWDataTransferLength = datalen;
@@ -170,11 +170,22 @@
 	cbw->bCBWCBLength = cmdlen;
 }
 
-static void
+static int
 get_csw (endpoint_t *ep, csw_t *csw)
 {
-	if (ep->dev->controller->bulk (ep, sizeof (csw_t), (u8 *) csw, 1))
+	if (ep->dev->controller->bulk (ep, sizeof (csw_t), (u8 *) csw, 1)) {
 		clear_stall (ep);
+		if (ep->dev->controller->bulk
+				(ep, sizeof (csw_t), (u8 *) csw, 1)) {
+			reset_transport (ep->dev);
+			return 1;
+		}
+	}
+	if (csw->dCSWTag != tag) {
+		reset_transport (ep->dev);
+		return 1;
+	}
+	return 0;
 }
 
 static int
@@ -209,7 +220,8 @@
 			}
 		}
 	}
-	get_csw (MSC_INST (dev)->bulk_in, &csw);
+	if (get_csw (MSC_INST (dev)->bulk_in, &csw))
+		return 1;
 	if (always_succeed == 1) {
 		// return success, regardless of message
 		return 0;
@@ -223,8 +235,9 @@
 		// no error, exit
 		return 0;
 	}
-	// error "check condition" or reserved error
-	request_sense (dev);
+	if (cb[0] != 0x03) /* 0x03 == request sense */
+		// error "check condition" or reserved error
+		request_sense (dev);
 	return 1;
 }