At Tue, 13 Dec 2011 14:32:59 +0530, Vinod Koul wrote:
+static int snd_compr_free(struct inode *inode, struct file *f) +{
- struct snd_compr_file *data = f->private_data;
- data->stream.ops->free(&data->stream);
Better to add a NULL check.
+static int +snd_compr_ioctl_avail(struct snd_compr_stream *stream, unsigned long arg) +{
- struct snd_compr_avail ioctl_avail;
- size_t avail;
- avail = snd_compr_calc_avail(stream, &ioctl_avail);
- ioctl_avail.avail = avail;
- if (copy_to_user((unsigned long __user *)arg,
&ioctl_avail, sizeof(ioctl_avail)))
Use a correct cast.
+static ssize_t snd_compr_write(struct file *f, const char __user *buf,
size_t count, loff_t *offset)+{
- struct snd_compr_file *data = f->private_data;
- struct snd_compr_stream *stream;
- size_t avail;
- int retval;
- BUG_ON(!data);
Avoid BUG_ON(). This is only for really critical bugs for which you must stop the whole machine. (BTW, snd_BUG_ON() is expanded to WARN_ON(), so it's not equivalent with BUG_ON().)
- stream = &data->stream;
- mutex_lock(&stream->device->lock);
- /* write is allowed when stream is running or has been steup */
- if (stream->runtime->state != SNDRV_PCM_STATE_SETUP &&
stream->runtime->state != SNDRV_PCM_STATE_RUNNING) {mutex_unlock(&stream->device->lock);return -EPERM;
Hm, I'm not sure whether EPERM is best here. In PCM, we used to use EBADFD.
+static unsigned int snd_compr_poll(struct file *f, poll_table *wait) +{
- struct snd_compr_file *data = f->private_data;
- struct snd_compr_stream *stream;
- size_t avail;
- int retval = 0;
- BUG_ON(!data);
Avoid BUG_ON().
- stream = &data->stream;
- mutex_lock(&stream->device->lock);
- if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING) {
retval = -ENXIO;goto out;- }
Whether to allow poll() at the state of PREPARE is an open question. You can think of an operation in a passive way via poll, such as,
open(); prepare(); while (poll()) write();
So, poll() could be useful even at PREPARE.
Takashi