From a79b4cdb52151dab5c5b2a86ab7619bc457470a8 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Thu, 25 Jul 2013 16:03:53 -0700 Subject: [PATCH] staging: comedi: usbdux: tidy up usbdux_ai_insn_read() Rename the local variable used for the private data pointer to the comedi "norm". Remove the unnecessary sanity check of the private data pointer. This function can only be called is the private data was allocated during the attach. Tidy up the exit path using goto to ensure that the semaphore is released. Return -EBUSY instead of 0 if the (*insn_read) cannot be done because a command is running. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/usbdux.c | 59 +++++++++++-------------- 1 file changed, 27 insertions(+), 32 deletions(-) diff --git a/drivers/staging/comedi/drivers/usbdux.c b/drivers/staging/comedi/drivers/usbdux.c index aebc728c9be9..a536fa3b6858 100644 --- a/drivers/staging/comedi/drivers/usbdux.c +++ b/drivers/staging/comedi/drivers/usbdux.c @@ -973,50 +973,45 @@ ai_cmd_exit: /* Mode 0 is used to get a single conversion on demand */ static int usbdux_ai_insn_read(struct comedi_device *dev, struct comedi_subdevice *s, - struct comedi_insn *insn, unsigned int *data) + struct comedi_insn *insn, + unsigned int *data) { + struct usbdux_private *devpriv = dev->private; + unsigned int chan = CR_CHAN(insn->chanspec); + unsigned int range = CR_RANGE(insn->chanspec); + unsigned int val; + int ret = -EBUSY; int i; - unsigned int one = 0; - int chan, range; - int err; - struct usbdux_private *this_usbduxsub = dev->private; - if (!this_usbduxsub) - return 0; + down(&devpriv->sem); - down(&this_usbduxsub->sem); - if (this_usbduxsub->ai_cmd_running) { - up(&this_usbduxsub->sem); - return 0; - } + if (devpriv->ai_cmd_running) + goto ai_read_exit; - /* sample one channel */ - chan = CR_CHAN(insn->chanspec); - range = CR_RANGE(insn->chanspec); /* set command for the first channel */ - this_usbduxsub->dux_commands[1] = create_adc_command(chan, range); + devpriv->dux_commands[1] = create_adc_command(chan, range); /* adc commands */ - err = send_dux_commands(dev, SENDSINGLEAD); - if (err < 0) { - up(&this_usbduxsub->sem); - return err; - } + ret = send_dux_commands(dev, SENDSINGLEAD); + if (ret < 0) + goto ai_read_exit; for (i = 0; i < insn->n; i++) { - err = receive_dux_commands(dev, SENDSINGLEAD); - if (err < 0) { - up(&this_usbduxsub->sem); - return 0; - } - one = le16_to_cpu(this_usbduxsub->insn_buffer[1]); - if (CR_RANGE(insn->chanspec) <= 1) - one = one ^ 0x800; + ret = receive_dux_commands(dev, SENDSINGLEAD); + if (ret < 0) + goto ai_read_exit; + + val = le16_to_cpu(devpriv->insn_buffer[1]); + if (range <= 1) + val ^= 0x800; - data[i] = one; + data[i] = val; } - up(&this_usbduxsub->sem); - return i; + +ai_read_exit: + up(&devpriv->sem); + + return ret ? ret : insn->n; } /************************************/ -- 2.20.1