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>

diff --git a/drivers/staging/comedi/drivers/comedi_isadma.c b/drivers/staging/comedi/drivers/comedi_isadma.c
index dbdea71d6b95b5e3c25a0a2fe2deb9eb57422a94..e856f01ca07716c8acb3881bbe8e4373a64beab5 100644 (file)
--- 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;
 }