Subject: Re: [PATCH v6 1/7] dt-bindings: reset: microchip,rst: Allow to replace cpu-syscon by an additional reg item

From: Herve Codina <[email-masked]>
Date: Tue, 1 Oct 2024 18:06:21 +0200

Hi Krystoff,

On Tue, 1 Oct 2024 08:43:23 +0200
Krzysztof Kozlowski <[email-masked]> wrote:

> On Mon, Sep 30, 2024 at 02:15:41PM +0200, Herve Codina wrote:
> > In the LAN966x PCI device use case, syscon cannot be used as syscon
> > devices do not support removal [1]. A syscon device is a core "system"
> > device and not a device available in some addon boards and so, it is not
> > supposed to be removed.  
> 
> That's not accurate. syscon is our own, Linux term which means also
> anything exposing set of registers.
> 
> If you need to unload syscons, implement it. syscon is the same resource
> as all others so should be handled same way.
> 
> > 
> > In order to remove the syscon device usage, allow the reset controller
> > to have a direct access to the address range it needs to use.  
> 
> So you map same address twice? That's not good, because you have no
> locking over concurrent register accesses.
> 

I will remove this patch and keep using the syscon node in the next
iteration.

Best regards,
Hervé