Introduce an inline helper to return the number of bytes that are
ready to read from the comedi_async buffer. Use the helper in the
comedi drivers that currently do the calculation as part of the
(*poll) operation.
Also, use the helper in comedi_fops where the calculation is used as
part of the subdevice going nonbusy.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregk@xxxxxxxxxxxxxxxxxxx>
---
v2: As pointed out by Ian Abbott, the original version of this patch
breaks when the 'count' values wrap around. The inline solution
he proposed is much cleaner.
drivers/staging/comedi/comedi_fops.c | 5 ++---
drivers/staging/comedi/comedidev.h | 5 +++++
drivers/staging/comedi/drivers/das16m1.c | 2 +-
drivers/staging/comedi/drivers/das1800.c | 2 +-
drivers/staging/comedi/drivers/ni_mio_common.c | 2 +-
drivers/staging/comedi/drivers/ni_pcidio.c | 2 +-
drivers/staging/comedi/drivers/pcl812.c | 2 +-
drivers/staging/comedi/drivers/pcl816.c | 2 +-
8 files changed, 13 insertions(+), 9 deletions(-)
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index c54ed42..d4904cc 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -997,7 +997,7 @@ static int do_bufinfo_ioctl(struct comedi_device *dev,
comedi_buf_read_free(s, bi.bytes_read);
if (comedi_is_subdevice_idle(s) &&
- async->buf_write_count == async->buf_read_count) {
+ comedi_buf_n_bytes_ready(s) == 0) {
do_become_nonbusy(dev, s);
}
}
@@ -2303,8 +2303,7 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes,
new_s = comedi_read_subdevice(dev, minor);
if (dev->attached && old_detach_count == dev->detach_count &&
s == new_s && new_s->async == async) {
- if (become_nonbusy ||
- async->buf_read_count - async->buf_write_count == 0)
+ if (become_nonbusy || comedi_buf_n_bytes_ready(s) == 0)
do_become_nonbusy(dev, s);
}
mutex_unlock(&dev->mutex);
diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h
index 8f4e44b..a115aed 100644
--- a/drivers/staging/comedi/comedidev.h
+++ b/drivers/staging/comedi/comedidev.h
@@ -333,6 +333,11 @@ static inline unsigned int bytes_per_sample(const struct comedi_subdevice *subd)
*/
int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev);
+static inline unsigned int comedi_buf_n_bytes_ready(struct comedi_subdevice *s)
+{
+ return s->async->buf_write_count - s->async->buf_read_count;
+}
+
unsigned int comedi_buf_write_alloc(struct comedi_subdevice *s, unsigned int n);
unsigned int comedi_buf_write_free(struct comedi_subdevice *s, unsigned int n);
diff --git a/drivers/staging/comedi/drivers/das16m1.c b/drivers/staging/comedi/drivers/das16m1.c
index ec039fb..c252ad2 100644
--- a/drivers/staging/comedi/drivers/das16m1.c
+++ b/drivers/staging/comedi/drivers/das16m1.c
@@ -477,7 +477,7 @@ static int das16m1_poll(struct comedi_device *dev, struct comedi_subdevice *s)
das16m1_handler(dev, status);
spin_unlock_irqrestore(&dev->spinlock, flags);
- return s->async->buf_write_count - s->async->buf_read_count;
+ return comedi_buf_n_bytes_ready(s);
}
static irqreturn_t das16m1_interrupt(int irq, void *d)
diff --git a/drivers/staging/comedi/drivers/das1800.c b/drivers/staging/comedi/drivers/das1800.c
index 8595190..b2f8391d 100644
--- a/drivers/staging/comedi/drivers/das1800.c
+++ b/drivers/staging/comedi/drivers/das1800.c
@@ -696,7 +696,7 @@ static int das1800_ai_poll(struct comedi_device *dev,
das1800_ai_handler(dev);
spin_unlock_irqrestore(&dev->spinlock, flags);
- return s->async->buf_write_count - s->async->buf_read_count;
+ return comedi_buf_n_bytes_ready(s);
}
static irqreturn_t das1800_interrupt(int irq, void *d)
diff --git a/drivers/staging/comedi/drivers/ni_mio_common.c b/drivers/staging/comedi/drivers/ni_mio_common.c
index 7737749..b2d6b1d 100644
--- a/drivers/staging/comedi/drivers/ni_mio_common.c
+++ b/drivers/staging/comedi/drivers/ni_mio_common.c
@@ -1878,7 +1878,7 @@ static int ni_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s)
#else
ni_sync_ai_dma(dev);
#endif
- count = s->async->buf_write_count - s->async->buf_read_count;
+ count = comedi_buf_n_bytes_ready(s);
spin_unlock_irqrestore(&dev->spinlock, flags);
return count;
diff --git a/drivers/staging/comedi/drivers/ni_pcidio.c b/drivers/staging/comedi/drivers/ni_pcidio.c
index 5fc74d6..b03105a 100644
--- a/drivers/staging/comedi/drivers/ni_pcidio.c
+++ b/drivers/staging/comedi/drivers/ni_pcidio.c
@@ -361,7 +361,7 @@ static int ni_pcidio_poll(struct comedi_device *dev, struct comedi_subdevice *s)
if (devpriv->di_mite_chan)
mite_sync_input_dma(devpriv->di_mite_chan, s);
spin_unlock(&devpriv->mite_channel_lock);
- count = s->async->buf_write_count - s->async->buf_read_count;
+ count = comedi_buf_n_bytes_ready(s);
spin_unlock_irqrestore(&dev->spinlock, irq_flags);
return count;
}
diff --git a/drivers/staging/comedi/drivers/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c
index 4c1b947..803e779 100644
--- a/drivers/staging/comedi/drivers/pcl812.c
+++ b/drivers/staging/comedi/drivers/pcl812.c
@@ -985,7 +985,7 @@ static int pcl812_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s)
spin_unlock_irqrestore(&dev->spinlock, flags);
- return s->async->buf_write_count - s->async->buf_read_count;
+ return comedi_buf_n_bytes_ready(s);
}
static int pcl812_ai_cancel(struct comedi_device *dev,
diff --git a/drivers/staging/comedi/drivers/pcl816.c b/drivers/staging/comedi/drivers/pcl816.c
index d9ca7fe..eda9986 100644
--- a/drivers/staging/comedi/drivers/pcl816.c
+++ b/drivers/staging/comedi/drivers/pcl816.c
@@ -516,7 +516,7 @@ static int pcl816_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s)
cfc_handle_events(dev, s);
- return s->async->buf_write_count - s->async->buf_read_count;
+ return comedi_buf_n_bytes_ready(s);
}
static int pcl816_ai_cancel(struct comedi_device *dev,
--
1.9.3
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