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staging: comedi: comedi_fops: cleanup comedi_poll()

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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@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
H Hartley Sweeten 2012-12-19 15:39:44 -07:00 committed by Greg Kroah-Hartman
parent 0e700923bf
commit ca081b1d7e
1 changed files with 22 additions and 31 deletions
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53
drivers/staging/comedi/comedi_fops.c
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@ -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);
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)) {
mask |= POLLOUT | POLLWRNORM;
}
}
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;
}