staging: comedi: comedi_isadma: fix "stalled" detect in comedi_isadma_disable_on_sample()

The "stalled" variable this function is used to detect if the DMA operation
is stalled while trying to disable DMA on a full comedi sample. The reset
of this variable should only occur when the remaining bytes of the DMA
transfer does not equal the remaining bytes from the last check.

Reported-by: coverity (CID 1271132)
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/staging/comedi/drivers/comedi_isadma.c b/drivers/staging/comedi/drivers/comedi_isadma.c
index dbdea71d6b95..e856f01ca077 100644
--- a/drivers/staging/comedi/drivers/comedi_isadma.c
+++ b/drivers/staging/comedi/drivers/comedi_isadma.c
@@ -91,9 +91,10 @@ unsigned int comedi_isadma_disable_on_sample(unsigned int dma_chan,
                         stalled++;
                         if (stalled > 10)
                                 break;
+                } else {
+                        residue = new_residue;
+                        stalled = 0;
                 }
-                residue = new_residue;
-                stalled = 0;
         }
         return residue;
 }