From: Steve Holland <sdh4@iastate.edu>
Date: Thu, 18 Jun 2009 22:37:49 +0000 (-0500)
Subject: USB: usbtmc: correct termination condition for reads.
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=4143d178e7b39c00d5277040c69a1522c4d98871;p=deliverable%2Flinux.git

USB: usbtmc: correct termination condition for reads.

Follow T&M convention of obeying EOM flag.  Avoid exception cases where
instrument response size matches a buffer size.

Signed-off-by: Steve Holland <sdh4@iastate.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 91d3a94eeaa0..6395f22a58e1 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -485,7 +485,8 @@ static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 		}
 
 		done += n_characters;
-		if (n_characters < USBTMC_SIZE_IOBUFFER)
+		/* Terminate if end-of-message bit recieved from device */
+		if ((buffer[8] &  0x01) && (actual >= n_characters + 12))
 			remaining = 0;
 		else
 			remaining -= n_characters;