On 26/01/15 21:20, H Hartley Sweeten wrote:
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@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/pcl812.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
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);
}
Reviewed-by: Ian Abbott <abbotti@xxxxxxxxx>
--
-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=-
-=( Web: http://www.mev.co.uk/ )=-
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