linux-kernel - Re: [PATCH v2 05/26] bus: simple-pm-bus: Populate child nodes at probe

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Message-ID: <20250519162443.20396e73@bootlin.com>
Date: Mon, 19 May 2025 16:24:43 +0200
From: Herve Codina <herve.codina@...tlin.com>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: Andrew Lunn <andrew@...n.ch>, Greg Kroah-Hartman
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Subject: Re: [PATCH v2 05/26] bus: simple-pm-bus: Populate child nodes at
 probe

Hi Andy,

On Mon, 19 May 2025 15:06:33 +0300
Andy Shevchenko <andriy.shevchenko@...ux.intel.com> wrote:

> On Mon, May 19, 2025 at 01:58:18PM +0200, Herve Codina wrote:
> > On Thu, 8 May 2025 17:27:52 +0300
> > Andy Shevchenko <andriy.shevchenko@...ux.intel.com> wrote:  
> > > On Wed, May 07, 2025 at 09:12:47AM +0200, Herve Codina wrote:  
> 
> ...
> 
> > > >  		if (of_property_match_string(np, "compatible", match->compatible) == 0)    
> > > 
> > > Side note, there is an fwnode_is_device_compatible() API for such cases. And IIRC
> > > there is also OF variant of it.  
> > 
> > fwnode_device_is_compatible() checked for all compatible string. I mean, if
> > we have compatible = "foo,custom-bus", "simple-bus";
> > fwnode_device_is_compatible() checking against "simple-bus" returns true.
> > 
> > Here, we want "simple-bus" as the first position in the compatible string.
> > In other word, we want to match the more specific compatible string as
> > mentioned in the comment.  
> 
> I admit I'm not an expert in DT, but why is the compatibility position
> dependent?
> 
> ...
> 
> > > > +	if (pdev->dev.of_node)    
> > > 
> > > Why do you need this check? AFAICS it dups the one the call has already in it.  
> > 
> > of_platform_populate() was called only if an OF node is present.
> > I want to call of_platform_depopulate() on removal also only if an OF node
> > is present.
> > 
> > I don't see the other call that duplicated this check.
> > 
> > Can you clarify?  
> 
> The of_...() is already NULL-aware (AFAICS), why do you need the duplicated
> check?

Oh, I see. I was focused on previous of_device_get_match_data() call.
My bad.

Indeed, you're right, I can call directly of_platform_depopulate() without
checking pdev->dev.of_node before the call. The check is already present
in of_platform_depopulate() itself.

I will do that in the next iteration.

Thanks for pointing out.

Best regards,
Hervé