staging: comedi: usbdux: fix usbdux_pwm_cancel()

Add the missing down/up of the semaphore to prevent other commands
from being issued to the usb device while the pwn is being stopped.

Rename the local variable used for the private data pointer to the
comedi "norm".

Make sure to check that usbdux_pwm_stop() was successful before
sending command to the usb device to stop the pwm.

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>
This commit is contained in:
H Hartley Sweeten 2013-07-25 16:07:20 -07:00 committed by Greg Kroah-Hartman
parent 38f0683502
commit 96ca37047e
1 changed files with 13 additions and 5 deletions

View File

@ -1430,17 +1430,25 @@ static int usbdux_pwm_stop(struct comedi_device *dev, int do_unlink)
return ret;
}
/* force unlink - is called by comedi */
static int usbdux_pwm_cancel(struct comedi_device *dev,
struct comedi_subdevice *s)
{
struct usbdux_private *this_usbduxsub = dev->private;
int res = 0;
struct usbdux_private *devpriv = dev->private;
int ret;
down(&devpriv->sem);
/* unlink only if it is really running */
res = usbdux_pwm_stop(dev, this_usbduxsub->pwm_cmd_running);
ret = usbdux_pwm_stop(dev, devpriv->pwm_cmd_running);
if (ret)
goto pwm_cancel_exit;
return send_dux_commands(dev, SENDPWMOFF);
ret = send_dux_commands(dev, SENDPWMOFF);
pwm_cancel_exit:
up(&devpriv->sem);
return ret;
}
static void usbduxsub_pwm_irq(struct urb *urb)