[PATCH 4.15 012/128] staging: comedi: fix comedi_nsamples_left.

[Greg Kroah-Hartman]

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Frank Mori Hess <fmh6jj@xxxxxxxxx>

commit a42ae5905140c324362fe5036ae1dbb16e4d359c upstream.

A rounding error was causing comedi_nsamples_left to
return the wrong value when nsamples was not a multiple
of the scan length.

Cc: <stable@xxxxxxxxxxxxxxx> # v4.4+
Signed-off-by: Frank Mori Hess <fmh6jj@xxxxxxxxx>
Reviewed-by: Ian Abbott <abbotti@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/staging/comedi/drivers.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -484,8 +484,7 @@ unsigned int comedi_nsamples_left(struct
 	struct comedi_cmd *cmd = &async->cmd;
 
 	if (cmd->stop_src == TRIG_COUNT) {
-		unsigned int nscans = nsamples / cmd->scan_end_arg;
-		unsigned int scans_left = __comedi_nscans_left(s, nscans);
+		unsigned int scans_left = __comedi_nscans_left(s, cmd->stop_arg);
 		unsigned int scan_pos =
 		    comedi_bytes_to_samples(s, async->scan_progress);
 		unsigned long long samples_left = 0;