24 Oct
2023
24 Oct
'23
1:12 p.m.
On Mon, Oct 23, 2023 at 05:50:00PM +0200, Takashi Iwai wrote:
On Mon, 23 Oct 2023 17:06:57 +0200, Matias Ezequiel Vara Larsen wrote:
+static int virtsnd_pcm_ack(struct snd_pcm_substream *substream) +{
- struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream);
- struct virtio_snd_queue *queue = virtsnd_pcm_queue(vss);
- unsigned long flags;
- struct snd_pcm_runtime *runtime = vss->substream->runtime;
- ssize_t appl_pos = frames_to_bytes(runtime, runtime->control->appl_ptr);
- ssize_t buf_size = frames_to_bytes(runtime, runtime->buffer_size);
- int rc;
- spin_lock_irqsave(&queue->lock, flags);
- spin_lock(&vss->lock);
- ssize_t bytes = (appl_pos - vss->appl_ptr) % buf_size;
The variable declaration should be moved to the beginning of the function.
Also, there can be a overlap beyond runtime->boundary (which easily happens for 32bit apps), so the calculation can be a bit more complex with conditional.
Should I use as an example `cs46xx_playback/capture_transfer()` which relies on the `snd_pcm_indirect_playback/capture_transfer()`? It looks like it does already that calculation.
Thanks, Matias.