Re: [PATCH] soundwire: debugfs: use controller id instead of link_id

[Pierre-Louis Bossart]

On 1/21/21 6:03 AM, Srinivas Kandagatla wrote:
> On 19/01/2021 19:09, Pierre-Louis Bossart wrote:
> > > currently we have
> > > /sys/kernel/debug/soundwire/master-*
> > >
> > > Are you suggesting that we have something like this:
> > >
> > > /sys/kernel/debug/soundwire/xyz-controller/master-<LINK-ID> ??
> >
> > Yes this is what I was thinking about.
>
> Vinod/Pierre,
>
> One Question here,
>
> Why is link_id part of "struct sdw_bus", should it not be part of 
> "struct sdw_master_device " ?
>
> Given that "There is one Link per each Master"

it's true that link == master == bus at the concept level.

but we have an existing code base with different structures and we can't 
break too many things at once.

In the existing flow, the 'bus' is created and setup first, the 
sdw_bus_master_add() routine takes a 'bus' argument, and the link_id is 
already set. This routine only creates a device and in the rest of the 
code we keep using the 'bus' pointer, so there's no real short-term 
scope for moving the information into the 'sdw_master_device' structure 
- that would be a lot of surgery when nothing is really broken.