[PATCH] usb: Fix timeout check in usb_control_msg

[Ronan Dalton]

The timeout check after the while loop in the usb_control_msg function
checks for equality with zero, which is incorrect because timeout will
actually be -1 after exiting the while loop due to a timeout.

Currently this means that -1 is usually returned by this function when
-ETIMEDOUT should have been returned instead.

Fix this by comparing timeout with -1 instead. Add a check for
timeout being negative at the start of the function and return -EINVAL
in that case, since a negative timeout doesn't make sense either.

Signed-off-by: Ronan Dalton <ronan.dalton at alliedtelesis.co.nz>
Cc: Marek Vasut <marex at denx.de>
Cc: Philip Oberfichtner <pro at denx.de>
---
 common/usb.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/common/usb.c b/common/usb.c
index 6a4ad346f4b..2cbc432b131 100644
--- a/common/usb.c
+++ b/common/usb.c
@@ -226,6 +226,9 @@ int usb_control_msg(struct usb_device *dev, unsigned int pipe,
 	ALLOC_CACHE_ALIGN_BUFFER(struct devrequest, setup_packet, 1);
 	int err;
 
+	if (timeout < 0)
+		return -EINVAL;
+
 	if ((timeout == 0) && (!asynch_allowed)) {
 		/* request for a asynch control pipe is not allowed */
 		return -EINVAL;
@@ -259,7 +262,7 @@ int usb_control_msg(struct usb_device *dev, unsigned int pipe,
 		mdelay(1);
 	}
 
-	if (timeout == 0)
+	if (timeout == -1)
 		return -ETIMEDOUT;
 
 	if (dev->status)
-- 
2.53.0