On Thu, 10 Jun 2021 22:53:26 +0200,
Pierre-Louis Bossart wrote:
>
> +/* update SPIB register with appl position */
> +int hda_dsp_pcm_ack(struct snd_sof_dev *sdev, struct snd_pcm_substream *substream)
> +{
> + struct hdac_stream *hstream = substream->runtime->private_data;
> + struct hdac_ext_stream *stream = stream_to_hdac_ext_stream(hstream);
> + struct snd_pcm_runtime *runtime = substream->runtime;
> + ssize_t appl_pos, buf_size;
> + u32 spib;
> +
> + if (!hda_disable_rewinds)
> + return 0;
> +
> + /*
> + * paranoia check: if a rewind request took place after the RUN bits were programmed,
> + * deny it since hardware only supports monotonic (modulo) increments for SPIB.
> + */
> + if (hstream->running) {
> + if (runtime->control->appl_ptr < stream->old_appl_ptr)
> + return -EINVAL;
This condition won't be enough when the appl_ptr overlap the buffer
boundary. It's still possible on 32bit architecture.
thanks,
Takashi
