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From: Boris Brezillon <boris.brezillon@collabora.com>
To: Vitor Soares <Vitor.Soares@synopsys.com>
Cc: "mark.rutland@arm.com" <mark.rutland@arm.com>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"Joao.Pinto@synopsys.com" <Joao.Pinto@synopsys.com>,
	"bbrezillon@kernel.org" <bbrezillon@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>,
	"linux-i3c@lists.infradead.org" <linux-i3c@lists.infradead.org>
Subject: Re: [PATCH 2/4] i3c: master: Check if devices have i3c_dev_boardinfo on i3c_master_add_i3c_dev_locked()
Date: Thu, 29 Aug 2019 18:37:21 +0200
Message-ID: <20190829183721.33a4664d@collabora.com> (raw)
In-Reply-To: <SN6PR12MB26550ABF84AD52C52DE801CFAEA20@SN6PR12MB2655.namprd12.prod.outlook.com>

On Thu, 29 Aug 2019 16:33:43 +0000
Vitor Soares <Vitor.Soares@synopsys.com> wrote:

> From: Boris Brezillon <boris.brezillon@collabora.com>
> Date: Thu, Aug 29, 2019 at 17:15:20
> 
> > On Thu, 29 Aug 2019 15:57:32 +0000
> > Vitor Soares <Vitor.Soares@synopsys.com> wrote:
> >   
> > > -----Original Message-----
> > > From: Boris Brezillon 
> > > <boris.brezillon@collabora.com> 
> > > Sent: Thursday, August 29, 2019 4:25 
> > > PM
> > > To: Vitor Soares <Vitor.Soares@synopsys.com>
> > > Cc: 
> > > linux-kernel@vger.kernel.org; devicetree@vger.kernel.org; 
> > > linux-i3c@lists.infradead.org; bbrezillon@kernel.org; robh+dt@kernel.org; 
> > > mark.rutland@arm.com; Joao.Pinto@synopsys.com
> > > 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@synopsys.com> wrote:
> > >   
> > > > From: Boris Brezillon     
> > > <boris.brezillon@collabora.com>  
> > > > Date: Thu, Aug 29, 2019 at 15:39:41
> > > >     
> > >   
> > > > > On Thu, 29 Aug 2019 16:39:18 +0200
> > > > > Boris Brezillon <boris.brezillon@collabora.com> wrote:
> > > > >       
> > > > > > On Thu, 29 Aug 2019 14:00:44 +0000
> > > > > > Vitor Soares <Vitor.Soares@synopsys.com> wrote:
> > > > > >       
> > > > > > > Hi Boris,
> > > > > > > 
> > > > > > > From: Boris Brezillon <boris.brezillon@collabora.com>
> > > > > > > Date: Thu, Aug 29, 2019 at 11:44:57
> > > > > > >         
> > > > > > > > On Thu, 29 Aug 2019 12:19:33 +0200
> > > > > > > > Vitor Soares <Vitor.Soares@synopsys.com> 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.  
> > 
> > Oh, my bad, I see what you mean now. This is definitely a bug and should
> > have the Fixes tags. I mean, even if we don't care about dynamic
> > address assignment, I3C drivers might care about the ->of_node that's
> > attached to the device.  
> 
> I didn't consider a bug because in dt-bindings says to not use 'assigned 
> address' if SA = 0.

The fact that we don't try to assign a predefined dynamic address
when !SA is indeed not a bug, but failing to propagate the ->of_node
info to the i3c_device is one.

> Do you think there is a better way to solve it?

Your patch is correct, I just proposed a few adjustments.

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  reply index

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-29 10:19 [PATCH 0/4] i3c: remove device if failed on pre_assign_dyn_addr() Vitor Soares
2019-08-29 10:19 ` [PATCH 1/4] i3c: master: detach and free device if pre_assign_dyn_addr() fails Vitor Soares
2019-08-29 10:41   ` Boris Brezillon
2019-08-29 13:53     ` Vitor Soares
2019-08-29 14:35       ` Boris Brezillon
2019-08-29 15:23         ` Vitor Soares
2019-08-29 15:37           ` Boris Brezillon
2019-08-29 16:23             ` Vitor Soares
2019-08-29 10:19 ` [PATCH 2/4] i3c: master: Check if devices have i3c_dev_boardinfo on i3c_master_add_i3c_dev_locked() Vitor Soares
2019-08-29 10:44   ` Boris Brezillon
2019-08-29 14:00     ` Vitor Soares
2019-08-29 14:39       ` Boris Brezillon
2019-08-29 14:39         ` Boris Brezillon
2019-08-29 15:07           ` Vitor Soares
2019-08-29 15:24             ` Boris Brezillon
2019-08-29 15:57               ` Vitor Soares
2019-08-29 16:15                 ` Boris Brezillon
2019-08-29 16:33                   ` Vitor Soares
2019-08-29 16:37                     ` Boris Brezillon [this message]
2019-08-29 16:27   ` Boris Brezillon
2019-08-29 10:19 ` [PATCH 3/4] dt-bindings: i3c: Make 'assigned-address' valid if static address != 0 Vitor Soares
2019-08-29 10:51   ` Boris Brezillon
2019-08-29 14:06     ` Vitor Soares
2019-08-29 10:19 ` [PATCH 4/4] i3c: master: dw: reattach device on first available location of address table Vitor Soares
2019-08-29 11:15   ` Boris Brezillon
2019-08-29 14:09     ` Vitor Soares

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