[patch 037/164] USB: FHCI: cq_get() should check kfifo_out()s return value

Greg KH
2010-07-01T20:50:08Z

2.6.33-stable review patch. If anyone has any objections, please let me know.

------------------

From: Anton Vorontsov <avorontsov@mvista.com>

commit 7f1cccd3ec8789e52897bc34420ca81a5e2edeab upstream.

Since commit 7acd72eb85f1c7a15e8b5eb554994949241737f1 ("kfifo: rename
kfifo_put... into kfifo_in... and kfifo_get... into kfifo_out..."),
kfifo_out() is marked __must_check, and that causes gcc to produce
lots of warnings like this:

CC drivers/usb/host/fhci-mem.o
In file included from drivers/usb/host/fhci-hcd.c:34:
drivers/usb/host/fhci.h: In function 'cq_get':
drivers/usb/host/fhci.h:520: warning: ignoring return value of 'kfifo_out', declared with attribute warn_unused_result
...

This patch fixes the issue by properly checking the return value.

Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/usb/host/fhci.h | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

--- a/drivers/usb/host/fhci.h
+++ b/drivers/usb/host/fhci.h
@@ -20,6 +20,7 @@

#include <linux/kernel.h>
#include <linux/types.h>
+#include <linux/bug.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/kfifo.h>
@@ -515,9 +516,13 @@ static inline int cq_put(struct kfifo *k

static inline void *cq_get(struct kfifo *kfifo)
{
- void *p = NULL;
+ unsigned int sz;
+ void *p;
+
+ sz = kfifo_out(kfifo, (void *)&p, sizeof(p));
+ if (sz != sizeof(p))
+ return NULL;

- kfifo_out(kfifo, (void *)&p, sizeof(p));
return p;
}