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 37cc5e45f10c4f78e6c19913aeab20f095f0c839..3ffb1ea2ecc87ba462d4a472c3bde08ed95d442f 100644 (file)
--- 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);
        }