Re: [RFC PATCH] ALSA: pci: add PreSonus Quantum PCI driver
Markus Elfring <[email protected]>
| Newsgroups | org.kernel.vger.linux-doc,org.kernel.vger.linux-kernel,org.kernel.vger.linux-sound |
|---|---|
| Message-ID | <[email protected]> |
…
> +++ b/sound/pci/quantum/quantum_dma.c
> @@ -0,0 +1,853 @@
…
> +static ssize_t cpu_latency_us_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
…
> + mutex_lock(&chip->dma_mutex);
> + chip->cpu_latency_us = value;
> + if (READ_ONCE(chip->stream_active))
> + quantum_cpu_latency_qos_apply(chip);
> + mutex_unlock(&chip->dma_mutex);
> +
> + return count;
> +}
…
Under which circumstances would you become interested to apply a statement
like “guard(mutex)(&chip->dma_mutex);”?
https://elixir.bootlin.com/linux/v7.2/source/include/linux/mutex.h#L253
Regards,
Markus