staging: comedi: drivers do not need to reset the async->cur_chan

The comedi core calls comedi_buf_reset() before starting an async command
(*do_cmd) and after returning a subdevice to an idle state (*cancel).

The drivers do not need to reset the async->cur_chan in those functions.
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>

drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c

@@ -629,7 +629,6 @@ static int apci3120_cancel(struct comedi_device *dev,
 	inb(dev->iobase + APCI3120_RESET_FIFO);
 	inw(dev->iobase + APCI3120_RD_STATUS);
 	devpriv->ui_AiActualScan = 0;
-	s->async->cur_chan = 0;
 	devpriv->ui_DmaActualBuffer = 0;
 
 	devpriv->ai_running = 0;
@@ -758,7 +757,6 @@ static int apci3120_cyclic_ai(int mode,
 	/* END JK 07.05.04: Comparison between WIN32 and Linux driver */
 
 	devpriv->ui_AiActualScan = 0;
-	s->async->cur_chan = 0;
 	devpriv->ui_DmaActualBuffer = 0;
 
 	/* value for timer2  minus -2 has to be done */

drivers/staging/comedi/drivers/adl_pci9118.c

@@ -575,7 +575,6 @@ static int pci9118_ai_cancel(struct comedi_device *dev,
 
 	devpriv->ai_act_scan = 0;
 	devpriv->ai_act_dmapos = 0;
-	s->async->cur_chan = 0;
 	s->async->inttrig = NULL;
 	devpriv->ai_neverending = 0;
 	devpriv->dma_actbuf = 0;
@@ -1120,7 +1119,6 @@ static int pci9118_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 
 	devpriv->ai_act_scan = 0;
 	devpriv->ai_act_dmapos = 0;
-	s->async->cur_chan = 0;
 
 	if (devpriv->usedma) {
 		Compute_and_setup_dma(dev, s);

drivers/staging/comedi/drivers/adv_pci1710.c

@@ -731,7 +731,6 @@ static int pci171x_ai_cancel(struct comedi_device *dev,
 	}
 
 	devpriv->ai_act_scan = 0;
-	s->async->cur_chan = 0;
 
 	return 0;
 }
@@ -931,7 +930,6 @@ static int pci171x_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 	outb(0, dev->iobase + PCI171x_CLRINT);
 
 	devpriv->ai_act_scan = 0;
-	s->async->cur_chan = 0;
 
 	devpriv->CntrlReg &= Control_CNT0;
 	if ((cmd->flags & CMDF_WAKE_EOS) == 0)

drivers/staging/comedi/drivers/ni_atmio16d.c

@@ -300,7 +300,6 @@ static int atmio16d_ai_cmd(struct comedi_device *dev,
 	 * It is still uber-experimental */
 
 	reset_counters(dev);
-	s->async->cur_chan = 0;
 
 	/* check if scanning multiple channels */
 	if (cmd->chanlist_len < 2) {

drivers/staging/comedi/drivers/pcl812.c

@@ -809,7 +809,6 @@ static int pcl812_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 
 	devpriv->ai_act_scan = 0;
 	devpriv->ai_poll_ptr = 0;
-	s->async->cur_chan = 0;
 
 	/*  don't we want wake up every scan? */
 	if (cmd->flags & CMDF_WAKE_EOS) {

drivers/staging/comedi/drivers/pcl816.c

@@ -509,7 +509,6 @@ static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 	udelay(1);
 
 	devpriv->ai_act_scan = 0;
-	s->async->cur_chan = 0;
 	devpriv->ai_cmd_running = 1;
 	devpriv->ai_poll_ptr = 0;
 	devpriv->ai_cmd_canceled = 0;

drivers/staging/comedi/drivers/usbdux.c

@@ -698,9 +698,6 @@ static int usbdux_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 	if (devpriv->ai_cmd_running)
 		goto ai_cmd_exit;
 
-	/* set current channel of the running acquisition to zero */
-	s->async->cur_chan = 0;
-
 	devpriv->dux_commands[1] = len;
 	for (i = 0; i < len; ++i) {
 		unsigned int chan = CR_CHAN(cmd->chanlist[i]);
@@ -996,9 +993,6 @@ static int usbdux_ao_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 	if (devpriv->ao_cmd_running)
 		goto ao_cmd_exit;
 
-	/* set current channel of the running acquisition to zero */
-	s->async->cur_chan = 0;
-
 	/* we count in steps of 1ms (125us) */
 	/* 125us mode not used yet */
 	if (0) {		/* (devpriv->high_speed) */

drivers/staging/comedi/drivers/usbduxfast.c

@@ -479,8 +479,6 @@ static int usbduxfast_ai_cmd(struct comedi_device *dev,
 		up(&devpriv->sem);
 		return -EBUSY;
 	}
-	/* set current channel of the running acquisition to zero */
-	s->async->cur_chan = 0;
 
 	/*
 	 * ignore the first buffers from the device if there

drivers/staging/comedi/drivers/usbduxsigma.c

@@ -689,8 +689,6 @@ static int usbduxsigma_ai_cmd(struct comedi_device *dev,
 
 	down(&devpriv->sem);
 
-	/* set current channel of the running acquisition to zero */
-	s->async->cur_chan = 0;
 	for (i = 0; i < len; i++) {
 		unsigned int chan  = CR_CHAN(cmd->chanlist[i]);
 
@@ -988,9 +986,6 @@ static int usbduxsigma_ao_cmd(struct comedi_device *dev,
 
 	down(&devpriv->sem);
 
-	/* set current channel of the running acquisition to zero */
-	s->async->cur_chan = 0;
-
 	devpriv->ao_counter = devpriv->ao_timer;
 
 	if (cmd->start_src == TRIG_NOW) {