From 26234771c1a53b0a3bf69c161d79cd37c77ebd1a Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 22 Apr 2013 18:36:28 -0700 Subject: [PATCH] staging: comedi: das800: tidy up das800_do_insn_bits() Use a couple local variables, mask and bits, to clarify this function. Its only necessary to update the outputs if the mask indicates that the bits are changing. Modify this function accordingly. Also, use the subdevice 'state' variable to hold the actual output channel state instead of needing to get it from the private data and shift it. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/das800.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/drivers/staging/comedi/drivers/das800.c b/drivers/staging/comedi/drivers/das800.c index b68c7410611..4f6698dc76d 100644 --- a/drivers/staging/comedi/drivers/das800.c +++ b/drivers/staging/comedi/drivers/das800.c @@ -648,21 +648,22 @@ static int das800_do_insn_bits(struct comedi_device *dev, unsigned int *data) { struct das800_private *devpriv = dev->private; - int wbits; + unsigned int mask = data[0]; + unsigned int bits = data[1]; unsigned long irq_flags; - /* only set bits that have been masked */ - data[0] &= 0xf; - wbits = devpriv->do_bits >> 4; - wbits &= ~data[0]; - wbits |= data[0] & data[1]; - devpriv->do_bits = wbits << 4; + if (mask) { + s->state &= ~mask; + s->state |= (bits & mask); + devpriv->do_bits = s->state << 4; - spin_lock_irqsave(&dev->spinlock, irq_flags); - das800_ind_write(dev, CONTROL1_INTE | devpriv->do_bits, CONTROL1); - spin_unlock_irqrestore(&dev->spinlock, irq_flags); + spin_lock_irqsave(&dev->spinlock, irq_flags); + das800_ind_write(dev, CONTROL1_INTE | devpriv->do_bits, + CONTROL1); + spin_unlock_irqrestore(&dev->spinlock, irq_flags); + } - data[1] = wbits; + data[1] = s->state; return insn->n; } -- 2.41.0