Re: [RFC PATCH v2 3/5] ASoC: apple: Add MCA platform driver for Apple SoCs

From: Mark Brown
Date: Mon Jun 06 2022 - 16:18:04 EST


On Mon, Jun 06, 2022 at 09:19:08PM +0200, Martin Povišer wrote:

> +++ b/sound/soc/apple/mca.c
> @@ -0,0 +1,1122 @@
> +/*
> + * Apple SoCs MCA driver

Please add SPDX headers to all your files.

> + mca_modify(cl, serdes_conf,
> + SERDES_CONF_SOME_RST, SERDES_CONF_SOME_RST);
> + (void) readl_relaxed(cl->base + serdes_conf);

Please drop the cast, casts to/from void are generally a warning sign as
they're unneeded in C. If you want to document the barrier use a
comment or wrapper function.

> + /*
> + * Codecs require clocks at time of umute with the 'mute_stream' op.
> + * We need to enable them here at the latest (frontend prepare would
> + * be too late).
> + */
> + if (!mca_fe_clocks_in_use(fe_cl)) {
> + ret = mca_fe_enable_clocks(fe_cl);
> + if (ret < 0)
> + return ret;
> + }

This requirement is CODEC specific. It's fine to bodge around to
satisfy it though, especially given the restricted set of platforms this
can be used with.

> + fe_cl = &mca->clusters[cl->port_driver];
> + if (!mca_fe_clocks_in_use(fe_cl))
> + return 0; /* Nothing to do */
> +
> + cl->clocks_in_use[substream->stream] = false;
> +
> + if (!mca_fe_clocks_in_use(fe_cl))
> + mca_fe_disable_clocks(fe_cl);

Are you sure this doesn't need locking?

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