staging: comedi: usbduxsigma: cleanup the (*cancel) functions

The (*cancel) functions can only be called by the comedi core it the
(*auto_attach) completed successfully. That function sets the comedi_device
'private' variable before initializing the callbacks so the sanity checks
are unnecessary. Remove them.

Also, rename the 'this_usbduxsub' local variable to 'devpriv' as this is
more common in comedi drivers.

Remove the unnecessary comments.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/usbduxsigma.c b/drivers/staging/comedi/drivers/usbduxsigma.c
index c0e2f9e4e5e2a14d7579351b34cb4c99e11786b4..eca29e4d7d3583894f397c517adbe1c3dd547d81 100644 (file)
--- a/drivers/staging/comedi/drivers/usbduxsigma.c
+++ b/drivers/staging/comedi/drivers/usbduxsigma.c
@@ -270,25 +270,15 @@ static void usbdux_ai_stop(struct usbduxsub *devpriv, int do_unlink)
        devpriv->ai_cmd_running = 0;
 }
 
-/*
- * This will cancel a running acquisition operation.
- * This is called by comedi but never from inside the driver.
- */
 static int usbdux_ai_cancel(struct comedi_device *dev,
                            struct comedi_subdevice *s)
 {
-       struct usbduxsub *this_usbduxsub;
-
-       /* force unlink of all urbs */
-       this_usbduxsub = dev->private;
-       if (!this_usbduxsub)
-               return -EFAULT;
+       struct usbduxsub *devpriv = dev->private;
 
-       /* prevent other CPUs from submitting new commands just now */
-       down(&this_usbduxsub->sem);
-       /* unlink only if the urb really has been submitted */
-       usbdux_ai_stop(this_usbduxsub, this_usbduxsub->ai_cmd_running);
-       up(&this_usbduxsub->sem);
+       down(&devpriv->sem);
+       /* unlink only if it is really running */
+       usbdux_ai_stop(devpriv, devpriv->ai_cmd_running);
+       up(&devpriv->sem);
 
        return 0;
 }
@@ -456,20 +446,15 @@ static void usbdux_ao_stop(struct usbduxsub *devpriv, int do_unlink)
        devpriv->ao_cmd_running = 0;
 }
 
-/* force unlink, is called by comedi */
 static int usbdux_ao_cancel(struct comedi_device *dev,
                            struct comedi_subdevice *s)
 {
-       struct usbduxsub *this_usbduxsub = dev->private;
+       struct usbduxsub *devpriv = dev->private;
 
-       if (!this_usbduxsub)
-               return -EFAULT;
-
-       /* prevent other CPUs from submitting a command just now */
-       down(&this_usbduxsub->sem);
+       down(&devpriv->sem);
        /* unlink only if it is really running */
-       usbdux_ao_stop(this_usbduxsub, this_usbduxsub->ao_cmd_running);
-       up(&this_usbduxsub->sem);
+       usbdux_ao_stop(devpriv, devpriv->ao_cmd_running);
+       up(&devpriv->sem);
 
        return 0;
 }
@@ -1627,19 +1612,15 @@ static void usbdux_pwm_stop(struct usbduxsub *devpriv, int do_unlink)
        devpriv->pwm_cmd_running = 0;
 }
 
-/* force unlink - is called by comedi */
 static int usbdux_pwm_cancel(struct comedi_device *dev,
                             struct comedi_subdevice *s)
 {
-       struct usbduxsub *this_usbduxsub = dev->private;
-
-       if (!this_usbduxsub)
-               return -EFAULT;
+       struct usbduxsub *devpriv = dev->private;
 
        /* unlink only if it is really running */
-       usbdux_pwm_stop(this_usbduxsub, this_usbduxsub->pwm_cmd_running);
+       usbdux_pwm_stop(devpriv, devpriv->pwm_cmd_running);
 
-       return send_dux_commands(this_usbduxsub, SENDPWMOFF);
+       return send_dux_commands(devpriv, SENDPWMOFF);
 }
 
 static void usbduxsub_pwm_irq(struct urb *urb)