[PATCH 09/11] staging: comedi: comedi_buf: clarify comedi_buf_read_alloc()

H Hartley Sweeten hsweeten at visionengravers.com
Fri Dec 21 16:42:22 UTC 2012


Clarify the check to make sure the number of bytes to allocate is
available.

Signed-off-by: H Hartley Sweeten <hsweeten at visionengravers.com>
Cc: Ian Abbott <abbobbi at mev.co.uk>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 drivers/staging/comedi/comedi_buf.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/comedi/comedi_buf.c b/drivers/staging/comedi/comedi_buf.c
index 246f577..1ec5aaa 100644
--- a/drivers/staging/comedi/comedi_buf.c
+++ b/drivers/staging/comedi/comedi_buf.c
@@ -298,10 +298,10 @@ EXPORT_SYMBOL(comedi_buf_read_n_available);
 /* allocates a chunk for the reader from filled (and munged) buffer space */
 unsigned comedi_buf_read_alloc(struct comedi_async *async, unsigned nbytes)
 {
-	if ((int)(async->buf_read_alloc_count + nbytes - async->munge_count) >
-	    0) {
-		nbytes = async->munge_count - async->buf_read_alloc_count;
-	}
+	int available = async->munge_count - async->buf_read_alloc_count;
+
+	if (nbytes > available)
+		nbytes = available;
 	async->buf_read_alloc_count += nbytes;
 	/* barrier insures read of munge_count occurs before we actually read
 	   data out of buffer */
-- 
1.8.0




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