[alsa-devel] [PATCH v2 4/6] soundwire: Handle multiple master instances in a stream

[Shreyas NC]

> >  static int do_bank_switch(struct sdw_stream_runtime *stream)
> >  {
> >-	struct sdw_master_runtime *m_rt = stream->m_rt;
> >+	struct sdw_master_runtime *m_rt = NULL;
> >  	const struct sdw_master_ops *ops;
> >-	struct sdw_bus *bus = m_rt->bus;
> >+	struct sdw_bus *bus = NULL;
> >  	int ret = 0;
> >-	ops = bus->ops;
> >-	/* Pre-bank switch */
> >-	if (ops->pre_bank_switch) {
> >-		ret = ops->pre_bank_switch(bus);
> >+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
> >+		bus = m_rt->bus;
> >+		ops = bus->ops;
> >+
> >+		/* Pre-bank switch */
> >+		if (ops->pre_bank_switch) {
> >+			ret = ops->pre_bank_switch(bus);
> >+			if (ret < 0) {
> >+				dev_err(bus->dev,
> >+					"Pre bank switch op failed: %d", ret);
> >+				return ret;
> >+			}
> >+		}
> >+
> >+		/* Bank switch */
> >+		ret = sdw_bank_switch(bus);
> >  		if (ret < 0) {
> >-			dev_err(bus->dev, "Pre bank switch op failed: %d", ret);
> >+			dev_err(bus->dev, "Bank switch failed: %d", ret);
> >  			return ret;
> >  		}
> You probably want to add a comment that in multi-link operation the actual
> bank_switch happens later and is done in a synchronized manner. This is lost
> if you just move code around and move the bank_switch into a loop.
> 

As mentioned in the commit log, this is just a boilerplate conversion to
loop over multiple m_rt and it is in the next patch that the
multilink_bank_switch() is added.
So, I can mention in the commit log of this patch that this is just a
preparatory patch for the next patch. And, also I will add the necessary
details in the next patch.

--Shreyas

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