From 2cc9854caf92526199935bc29685e253349362bc Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Wed, 22 Oct 2014 14:36:36 -0700 Subject: [PATCH] staging: comedi: cb_pcidas: introduce cb_pcidas_ao_load_fifo() Introduce a helper function to load the analog output FIFO. This fixes a bug in cb_pcidas_ao_inttrig(). That function was writing 'num_bytes' data values to the FIFO instead of 'num_points'. This results in twice the number of data values getting written to the FIFO. Use comedi_buf_read_samples() read the analog output samples from the async buffer. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/cb_pcidas.c | 54 +++++++++------------- 1 file changed, 22 insertions(+), 32 deletions(-) diff --git a/drivers/staging/comedi/drivers/cb_pcidas.c b/drivers/staging/comedi/drivers/cb_pcidas.c index e7ab6bcfa90b..a0d462fecf20 100644 --- a/drivers/staging/comedi/drivers/cb_pcidas.c +++ b/drivers/staging/comedi/drivers/cb_pcidas.c @@ -1134,32 +1134,39 @@ static int cb_pcidas_cancel(struct comedi_device *dev, return 0; } +static void cb_pcidas_ao_load_fifo(struct comedi_device *dev, + struct comedi_subdevice *s, + unsigned int nsamples) +{ + struct cb_pcidas_private *devpriv = dev->private; + struct comedi_cmd *cmd = &s->async->cmd; + unsigned int nbytes; + + if (cmd->stop_src == TRIG_COUNT && devpriv->ao_count < nsamples) + nsamples = devpriv->ao_count; + + nbytes = comedi_buf_read_samples(s, devpriv->ao_buffer, nsamples); + nsamples = nbytes / bytes_per_sample(s); + if (cmd->stop_src == TRIG_COUNT) + devpriv->ao_count -= nsamples; + + outsw(devpriv->ao_registers + DACDATA, devpriv->ao_buffer, nsamples); +} + static int cb_pcidas_ao_inttrig(struct comedi_device *dev, struct comedi_subdevice *s, unsigned int trig_num) { const struct cb_pcidas_board *thisboard = dev->board_ptr; struct cb_pcidas_private *devpriv = dev->private; - unsigned int num_bytes, num_points = thisboard->fifo_size; struct comedi_async *async = s->async; - struct comedi_cmd *cmd = &s->async->cmd; + struct comedi_cmd *cmd = &async->cmd; unsigned long flags; if (trig_num != cmd->start_arg) return -EINVAL; - /* load up fifo */ - if (cmd->stop_src == TRIG_COUNT && devpriv->ao_count < num_points) - num_points = devpriv->ao_count; - - num_bytes = cfc_read_array_from_buffer(s, devpriv->ao_buffer, - num_points * sizeof(short)); - num_points = num_bytes / sizeof(short); - - if (cmd->stop_src == TRIG_COUNT) - devpriv->ao_count -= num_points; - /* write data to board's fifo */ - outsw(devpriv->ao_registers + DACDATA, devpriv->ao_buffer, num_bytes); + cb_pcidas_ao_load_fifo(dev, s, thisboard->fifo_size); /* enable dac half-full and empty interrupts */ spin_lock_irqsave(&dev->spinlock, flags); @@ -1275,8 +1282,6 @@ static void handle_ao_interrupt(struct comedi_device *dev, unsigned int status) struct comedi_subdevice *s = dev->write_subdev; struct comedi_async *async = s->async; struct comedi_cmd *cmd = &async->cmd; - unsigned int half_fifo = thisboard->fifo_size / 2; - unsigned int num_points; unsigned long flags; if (status & DAEMI) { @@ -1295,23 +1300,8 @@ static void handle_ao_interrupt(struct comedi_device *dev, unsigned int status) async->events |= COMEDI_CB_EOA; } } else if (status & DAHFI) { - unsigned int num_bytes; + cb_pcidas_ao_load_fifo(dev, s, thisboard->fifo_size / 2); - /* figure out how many points we are writing to fifo */ - num_points = half_fifo; - if (cmd->stop_src == TRIG_COUNT && - devpriv->ao_count < num_points) - num_points = devpriv->ao_count; - num_bytes = - cfc_read_array_from_buffer(s, devpriv->ao_buffer, - num_points * sizeof(short)); - num_points = num_bytes / sizeof(short); - - if (cmd->stop_src == TRIG_COUNT) - devpriv->ao_count -= num_points; - /* write data to board's fifo */ - outsw(devpriv->ao_registers + DACDATA, devpriv->ao_buffer, - num_points); /* clear half-full interrupt latch */ spin_lock_irqsave(&dev->spinlock, flags); outw(devpriv->adc_fifo_bits | DAHFI, -- 2.39.2