RE: [PATCH 2/4] i3c: master: Check if devices have i3c_dev_boardinfo on i3c_master_add_i3c_dev_locked()

[Vitor Soares]

-----Original Message-----
From: Boris Brezillon 
<boris.brezillon@xxxxxxxxxxxxx> 
Sent: Thursday, August 29, 2019 4:25 
PM
To: Vitor Soares <Vitor.Soares@xxxxxxxxxxxx>
Cc: 
linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; 
linux-i3c@xxxxxxxxxxxxxxxxxxx; bbrezillon@xxxxxxxxxx; robh+dt@xxxxxxxxxx; 
mark.rutland@xxxxxxx; Joao.Pinto@xxxxxxxxxxxx
Subject: Re: [PATCH 2/4] 
i3c: master: Check if devices have i3c_dev_boardinfo on 
i3c_master_add_i3c_dev_locked()

On Thu, 29 Aug 2019 15:07:08 +0000
Vitor Soares <Vitor.Soares@xxxxxxxxxxxx> wrote:

> From: Boris Brezillon 
<boris.brezillon@xxxxxxxxxxxxx>
> Date: Thu, Aug 29, 2019 at 15:39:41
> 

> > On Thu, 29 Aug 2019 16:39:18 +0200
> > Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> wrote:
> >   
> > > On Thu, 29 Aug 2019 14:00:44 +0000
> > > Vitor Soares <Vitor.Soares@xxxxxxxxxxxx> wrote:
> > >   
> > > > Hi Boris,
> > > > 
> > > > From: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> > > > Date: Thu, Aug 29, 2019 at 11:44:57
> > > >     
> > > > > On Thu, 29 Aug 2019 12:19:33 +0200
> > > > > Vitor Soares <Vitor.Soares@xxxxxxxxxxxx> wrote:
> > > > >       
> > > > > > The I3C devices described in DT might not be attached to the master which
> > > > > > doesn't allow to assign a specific dynamic address.      
> > > > > 
> > > > > I remember testing this when developing the framework, so, unless
> > > > > another patch regressed it, it should already work. I suspect patch 1
> > > > > is actually the regressing this use case.      
> > > > 
> > > > For today it doesn't address the case where the device is described with 
> > > > static address = 0, which isn't attached to the controller.    
> > > 
> > > Hm, I'm pretty sure I had designed the code to support that case (see
> > > [1]). It might be buggy, but nothing we can't fix I guess.
> > >   
> > 
> > [1]https://urldefense.proofpoint.com/v2/url?u=https-3A__elixir.bootlin.com_linux_v5.3-2Drc6_source_drivers_i3c_master.c-23L1898&d=DwICAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=qVuU64u9x77Y0Kd0PhDK_lpxFgg6PK9PateHwjb_DY0&m=IXS1ygIgEo5vwajk0iwd5aBDVBzRnVTjO3cg4iBmGNc&s=HC-AcYm-AZPrUBoALioej_BDnqOtJHltr39Z2yPkuU4&e=   
> 
> That is only valid if you have olddev which will only exist if static 
> address != 0.

Hm, if you revert patch 1 (and assuming the device is properly defined
in the DT), you should have olddev != NULL when reaching that point. If
that's not the case there's a bug somewhere that should be fixed.

No, because the device is not attached.