From 99ca4e4613da5cb589de6b4127de75e520b32b43 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 23 Feb 2015 14:58:00 -0700 Subject: [PATCH] staging: comedi: amplc_dio200_common: remove 'spinlock' from struct dio200_subdev_8254 Currently this driver uses a spinlock in the 8254 subdevice (*insn_read), (*insn_write), and (*insn_config) functions. The comedi core checks if the subdevice is 'busy', in parse_insn(), before any of the subdevice functions are attempted. Remove the unnecessary spinlock. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- .../comedi/drivers/amplc_dio200_common.c | 23 ++++--------------- 1 file changed, 5 insertions(+), 18 deletions(-) diff --git a/drivers/staging/comedi/drivers/amplc_dio200_common.c b/drivers/staging/comedi/drivers/amplc_dio200_common.c index 48cdddc56110..08dab1fd91f2 100644 --- a/drivers/staging/comedi/drivers/amplc_dio200_common.c +++ b/drivers/staging/comedi/drivers/amplc_dio200_common.c @@ -101,7 +101,6 @@ struct dio200_subdev_8254 { unsigned int ofs; /* Counter base offset */ unsigned int clock_src[3]; /* Current clock sources */ unsigned int gate_src[3]; /* Current gate sources */ - spinlock_t spinlock; }; struct dio200_subdev_8255 { @@ -535,16 +534,12 @@ static int dio200_subdev_8254_read(struct comedi_device *dev, struct comedi_insn *insn, unsigned int *data) { - struct dio200_subdev_8254 *subpriv = s->private; int chan = CR_CHAN(insn->chanspec); unsigned int n; - unsigned long flags; - for (n = 0; n < insn->n; n++) { - spin_lock_irqsave(&subpriv->spinlock, flags); + for (n = 0; n < insn->n; n++) data[n] = dio200_subdev_8254_read_chan(dev, s, chan); - spin_unlock_irqrestore(&subpriv->spinlock, flags); - } + return insn->n; } @@ -553,16 +548,12 @@ static int dio200_subdev_8254_write(struct comedi_device *dev, struct comedi_insn *insn, unsigned int *data) { - struct dio200_subdev_8254 *subpriv = s->private; int chan = CR_CHAN(insn->chanspec); unsigned int n; - unsigned long flags; - for (n = 0; n < insn->n; n++) { - spin_lock_irqsave(&subpriv->spinlock, flags); + for (n = 0; n < insn->n; n++) dio200_subdev_8254_write_chan(dev, s, chan, data[n]); - spin_unlock_irqrestore(&subpriv->spinlock, flags); - } + return insn->n; } @@ -643,12 +634,9 @@ static int dio200_subdev_8254_config(struct comedi_device *dev, struct comedi_insn *insn, unsigned int *data) { - struct dio200_subdev_8254 *subpriv = s->private; int ret = 0; int chan = CR_CHAN(insn->chanspec); - unsigned long flags; - spin_lock_irqsave(&subpriv->spinlock, flags); switch (data[0]) { case INSN_CONFIG_SET_COUNTER_MODE: if (data[1] > (I8254_MODE5 | I8254_BCD)) @@ -689,7 +677,7 @@ static int dio200_subdev_8254_config(struct comedi_device *dev, ret = -EINVAL; break; } - spin_unlock_irqrestore(&subpriv->spinlock, flags); + return ret < 0 ? ret : insn->n; } @@ -713,7 +701,6 @@ static int dio200_subdev_8254_init(struct comedi_device *dev, s->insn_write = dio200_subdev_8254_write; s->insn_config = dio200_subdev_8254_config; - spin_lock_init(&subpriv->spinlock); subpriv->ofs = offset; /* Initialize channels. */