staging: comedi: usbdux: use common code path to check the cmd->scan_begin_arg

There are currently separate code paths to check the scan_begin_arg based
of the USB speed. Refactor the code to use a common code path and simplify
the code.

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/usbdux.c b/drivers/staging/comedi/drivers/usbdux.c
index 1ba6dd93dd367473d939f5605ce6a969009116db..be4c2db21cc8cfb4980c27c221c3906b15add02e 100644 (file)
--- a/drivers/staging/comedi/drivers/usbdux.c
+++ b/drivers/staging/comedi/drivers/usbdux.c
@@ -517,8 +517,7 @@ static int usbdux_ai_cmdtest(struct comedi_device *dev,
                             struct comedi_subdevice *s, struct comedi_cmd *cmd)
 {
        struct usbdux_private *this_usbduxsub = dev->private;
-       int err = 0, i;
-       unsigned int tmp_timer;
+       int err = 0;
 
        /* Step 1 : check if triggers are trivially valid */
 
@@ -549,6 +548,10 @@ static int usbdux_ai_cmdtest(struct comedi_device *dev,
                err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
 
        if (cmd->scan_begin_src == TRIG_TIMER) {
+               /* full speed does 1kHz scans every USB frame */
+               unsigned int arg = 1000000;
+               unsigned int min_arg = arg;
+
                if (this_usbduxsub->high_speed) {
                        /*
                         * In high speed mode microframes are possible.
@@ -556,33 +559,20 @@ static int usbdux_ai_cmdtest(struct comedi_device *dev,
                         * sample one channel. Thus, the more channels
                         * are in the channel list the more time we need.
                         */
-                       i = 1;
+                       int i = 1;
+
                        /* find a power of 2 for the number of channels */
-                       while (i < (cmd->chanlist_len))
+                       while (i < cmd->chanlist_len)
                                i = i * 2;
 
-                       err |= comedi_check_trigger_arg_min(&cmd->
-                                                           scan_begin_arg,
-                                                           1000000 / 8 * i);
-                       /* now calc the real sampling rate with all the
-                        * rounding errors */
-                       tmp_timer =
-                           ((unsigned int)(cmd->scan_begin_arg / 125000)) *
-                           125000;
-               } else {
-                       /* full speed */
-                       /* 1kHz scans every USB frame */
-                       err |= comedi_check_trigger_arg_min(&cmd->
-                                                           scan_begin_arg,
-                                                           1000000);
-                       /*
-                        * calc the real sampling rate with the rounding errors
-                        */
-                       tmp_timer = ((unsigned int)(cmd->scan_begin_arg /
-                                                  1000000)) * 1000000;
+                       arg /= 8;
+                       min_arg = arg * i;
                }
-               err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg,
-                                                  tmp_timer);
+               err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg,
+                                                   min_arg);
+               /* calc the real sampling rate with the rounding errors */
+               arg = (cmd->scan_begin_arg / arg) * arg;
+               err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg);
        }
 
        err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,