Re: [PATCH 2/3] soundwire: qcom: add auto enumeration support

From: Srinivas Kandagatla
Date: Fri Mar 05 2021 - 11:58:44 EST




On 05/03/2021 16:19, Pierre-Louis Bossart wrote:


The question is: what happens if that device is NOT described in the Device Tree data? The loop over bus->slaves will not find this device by comparing with known devID values, so the set_bit(i, bus->assigned) will not happen.

yes, that is true, There is no way we can assign a dev_number to the device which is not enumerated on the bus!

Am sure this is the same behavior with soundwire core too, atleast form the code I can see it sets the assigned bit for only the devices that are enumerated on the bus! Not all the devices specified in DT!
Unless I missed something!

I am talking about the other way around, where a device is present and enumerated on the bus but not listed in DT. In that case the hardware did assign a device number but bus->assigned will not be set.

thanks for your patience!

Ah, I understand it now!, yes that part is missing!

adding Something like what core does in qcom driver should fix it!

if (!found) {
sdw_slave_add(bus, &id, NULL);
dev_err(bus->dev, "Slave Entry not found\n");
}

--srini