From fd27ae76d29d59aa834bf26d45535b1ba09ab543 Mon Sep 17 00:00:00 2001
From: H Hartley Sweeten <hsweeten@visionengravers.com>
Date: Mon, 26 Jan 2015 14:20:15 -0700
Subject: staging: comedi: pcl812: fix logic error in pcl812_ai_setup_dma()

commit 92afc2b229038d7b962ae69de5b07bc6c1cf51bf inroduced a logic error
in the DMA size calculation.

If the 'nsamples' is greater than the 'unread_samples' then DMA needs to
be restarted. The current code checks it agains the 'max_samples'.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c
index 37cc5e4..3ffb1ea 100644
--- a/drivers/staging/comedi/drivers/pcl812.c
+++ b/drivers/staging/comedi/drivers/pcl812.c
@@ -559,8 +559,8 @@ static void pcl812_ai_setup_dma(struct comedi_device *dev,
 	 * unread samples and the number of samples remaining in the command.
 	 */
 	nsamples = comedi_nsamples_left(s, max_samples + unread_samples);
-	if (nsamples > max_samples) {
-		nsamples -= max_samples;
+	if (nsamples > unread_samples) {
+		nsamples -= unread_samples;
 		desc->size = comedi_samples_to_bytes(s, nsamples);
 		comedi_isadma_program(desc);
 	}
-- 
cgit v0.10.2