On 2012-12-19 22:39, H Hartley Sweeten wrote:
Consolidate the local variables 'read_subdev' and 'write_subdev' into a
single local variable 's'.
Use comedi_dev_from_minor() to simplify the return -ENODEV tests.
Use a goto in the !dev->attached test so that the mutex_unlock() call
is in a common place.
Cleanup the formating of the || in the read and write subdevice poll
code.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/comedi_fops.c | 49 +++++++++++++++---------------------
1 file changed, 20 insertions(+), 29 deletions(-)
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index f67b12a..093f403 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -1823,49 +1823,40 @@ static unsigned int comedi_poll(struct file *file, poll_table *wait)
{
unsigned int mask = 0;
const unsigned minor = iminor(file->f_dentry->d_inode);
- struct comedi_subdevice *read_subdev;
- struct comedi_subdevice *write_subdev;
struct comedi_file_info *info = comedi_file_info_from_minor(minor);
- struct comedi_device *dev;
+ struct comedi_device *dev = comedi_dev_from_minor(minor);
Isn't the comedi_dev_from_minor call a bit wasteful here if we have
already called comedi_file_info_from_minor? How about a
comedi_dev_from_file_info(info) function that can deal with info being
NULL, e.g.:
static inline struct comedi_device *
comedi_dev_from_file_info(struct comedi_file_info *info)
{
return info ? info->device : NULL;
}
Then you could use:
struct comedi_file_info *info = comedi_file_info_from_minor(minor);
struct comedi_device *dev = comedi_dev_from_file_info(info);
This also applies to patches 12, 13 and 25 in this series.
+ struct comedi_subdevice *s;
- if (info == NULL)
- return -ENODEV;
- dev = info->device;
- if (dev == NULL)
+ if (!dev)
return -ENODEV;
mutex_lock(&dev->mutex);
+
if (!dev->attached) {
DPRINTK("no driver configured on comedi%i\n", dev->minor);
- mutex_unlock(&dev->mutex);
- return 0;
+ goto done;
}
- mask = 0;
- read_subdev = comedi_read_subdevice(info);
- if (read_subdev) {
- poll_wait(file, &read_subdev->async->wait_head, wait);
- if (!read_subdev->busy
- || comedi_buf_read_n_available(read_subdev->async) > 0
- || !(comedi_get_subdevice_runflags(read_subdev) &
- SRF_RUNNING)) {
+ s = comedi_read_subdevice(info);
+ if (s) {
+ poll_wait(file, &s->async->wait_head, wait);
+ if (!s->busy || !(comedi_get_subdevice_runflags(s) & SRF_RUNNING) ||
+ comedi_buf_read_n_available(s->async) > 0)
mask |= POLLIN | POLLRDNORM;
- }
}
- write_subdev = comedi_write_subdevice(info);
- if (write_subdev) {
- poll_wait(file, &write_subdev->async->wait_head, wait);
- comedi_buf_write_alloc(write_subdev->async,
- write_subdev->async->prealloc_bufsz);
- if (!write_subdev->busy
- || !(comedi_get_subdevice_runflags(write_subdev) &
- SRF_RUNNING)
- || comedi_buf_write_n_allocated(write_subdev->async) >=
- bytes_per_sample(write_subdev->async->subdevice)) {
+
+ s = comedi_write_subdevice(info);
+ if (s) {
+ unsigned int bps = bytes_per_sample(s->async->subdevice);
+
+ poll_wait(file, &s->async->wait_head, wait);
+ comedi_buf_write_alloc(s->async, s->async->prealloc_bufsz);
+ if (!s->busy || !(comedi_get_subdevice_runflags(s) & SRF_RUNNING) ||
+ comedi_buf_write_n_allocated(s->async) >= bps)
mask |= POLLOUT | POLLWRNORM;
- }
}
+done:
mutex_unlock(&dev->mutex);
return mask;
}
--
-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=-
-=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=-
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