Re: [PATCH v4 05/13] soundwire: Add helpers for ports operations

[Vinod Koul <vinod.koul@intel.com>]

On Mon, Apr 23, 2018 at 08:27:46AM -0500, Pierre-Louis Bossart wrote:
> On 4/21/18 10:53 AM, Vinod Koul wrote:
> >On Sat, Apr 21, 2018 at 06:47:24AM -0700, Pierre-Louis Bossart wrote:
> >>
> >>>+static int sdw_enable_disable_slave_ports(struct sdw_bus *bus,
> >>>+				struct sdw_slave_runtime *s_rt,
> >>>+				struct sdw_port_runtime *p_rt, bool en)
> >>>+{
> >>>+	struct sdw_transport_params *t_params = &p_rt->transport_params;
> >>>+	u32 addr;
> >>>+	int ret;
> >>>+
> >>>+	if (bus->params.next_bank)
> >>>+		addr = SDW_DPN_CHANNELEN_B1(p_rt->num);
> >>>+	else
> >>>+		addr = SDW_DPN_CHANNELEN_B0(p_rt->num);
> >>>+
> >>>+	/*
> >>>+	 * Since bus doesn't support sharing a port across two streams,
> >>>+	 * it is safe to reset this register
> >>>+	 */
> >>>+	if (en)
> >>>+		ret = sdw_update(s_rt->slave, addr, 0xFF, p_rt->ch_mask);
> >>>+	else
> >>>+		ret = sdw_update(s_rt->slave, addr, 0xFF, 0x0);
> >>>+
> >>>+	if (ret < 0)
> >>>+		dev_err(&s_rt->slave->dev,
> >>>+			"Slave chn_en reg write failed:%d port:%d",
> >>>+			ret, t_params->port_num);
> >>>+
> >>>+	return ret;
> >>>+}
> >>
> >>Add a clarification that this routine only sets the enable/disable bits in
> >>the relevant bank, the actual enable/disable is done with a bank switch.
> >
> >Isn't that something spec tells the reader? this is a SDW concept that we
> >program bank and then switch to have the effect, so why would i add comment
> >for that?
> 
> To make sure people understand your code and follow the recommendation from
> the spec. It's legal to write directly in enable bits but it's not
> recommended at all. A standard spec is always interpreted in different ways,
> adding a comment helps.

will add a comment

-- 
~Vinod