linux-kernel - RE: [EXTERNAL] Re: [PATCH 1/4] [PATCH 1/4] reset: simple: Add syscon device compatible

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID:
 <BY3PR18MB46737EC23144183C5C272406A7FE2@BY3PR18MB4673.namprd18.prod.outlook.com>
Date: Fri, 14 Feb 2025 18:40:16 +0000
From: Wilson Ding <dingwei@...vell.com>
To: Philipp Zabel <p.zabel@...gutronix.de>,
        "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>,
        "devicetree@...r.kernel.org"
	<devicetree@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org"
	<linux-arm-kernel@...ts.infradead.org>
CC: "andrew@...n.ch" <andrew@...n.ch>,
        "gregory.clement@...tlin.com"
	<gregory.clement@...tlin.com>,
        "sebastian.hesselbarth@...il.com"
	<sebastian.hesselbarth@...il.com>,
        "robh@...nel.org" <robh@...nel.org>,
        "krzk+dt@...nel.org" <krzk+dt@...nel.org>,
        "conor+dt@...nel.org"
	<conor+dt@...nel.org>,
        Sanghoon Lee <salee@...vell.com>,
        Geethasowjanya Akula
	<gakula@...vell.com>
Subject: RE: [EXTERNAL] Re: [PATCH 1/4] [PATCH 1/4] reset: simple: Add syscon
 device compatible



> -----Original Message-----
> From: Philipp Zabel <p.zabel@...gutronix.de>
> Sent: Friday, February 14, 2025 10:03 AM
> To: Wilson Ding <dingwei@...vell.com>; linux-kernel@...r.kernel.org;
> devicetree@...r.kernel.org; linux-arm-kernel@...ts.infradead.org
> Cc: andrew@...n.ch; gregory.clement@...tlin.com;
> sebastian.hesselbarth@...il.com; robh@...nel.org; krzk+dt@...nel.org;
> conor+dt@...nel.org; Sanghoon Lee <salee@...vell.com>; Geethasowjanya
> Akula <gakula@...vell.com>
> Subject: [EXTERNAL] Re: [PATCH 1/4] [PATCH 1/4] reset: simple: Add syscon
> device compatible
> 
> On Fr, 2025-02-14 at 17: 13 +0000, Wilson Ding wrote: > > > -----Original
> Message----- > > From: Philipp Zabel <p. zabel@ pengutronix. de> > > Sent:
> Friday, February 14, 2025 3: 54 AM > > To: Wilson Ding
> <dingwei@ marvell. com>; 
> On Fr, 2025-02-14 at 17:13 +0000, Wilson Ding wrote:
> >
> > > -----Original Message-----
> > > From: Philipp Zabel <p.zabel@...gutronix.de>
> > > Sent: Friday, February 14, 2025 3:54 AM
> > > To: Wilson Ding <dingwei@...vell.com>; linux-kernel@...r.kernel.org;
> > > devicetree@...r.kernel.org; linux-arm-kernel@...ts.infradead.org
> > > Cc: andrew@...n.ch; gregory.clement@...tlin.com;
> > > sebastian.hesselbarth@...il.com; robh@...nel.org;
> > > krzk+dt@...nel.org;
> > > conor+dt@...nel.org; Sanghoon Lee <salee@...vell.com>;
> > > conor+Geethasowjanya
> > > Akula <gakula@...vell.com>
> > > Subject: [EXTERNAL] Re: [PATCH 1/4] [PATCH 1/4] reset: simple: Add
> > > syscon device compatible
> > >
> > > On Do, 2025-02-13 at 22:58 -0800, Wilson Ding wrote:
> > > > Introduce the new ops for updating reset line and getting status.
> > > > Thus, the reset controller can be accessed through either direct
> > > > I/O or regmap interfaces.
> > >
> > > Please don't add a new layer of function pointer indirection, just
> > > add a new struct reset_control_ops for the regmap variant.
> > >
> >
> > If just adding a new struct reset_control_ops for the regmap variant,
> > almost all the functions will be duplicated for regmap variant.
> > Besides reset_simple_regmap_assert/deassert(), we also need to have
> > the regmap version of reset_simple_update().
> 
> Yes. You could also duplicate/fold update() into assert/deassert().
> It is trivial enough and the compiler will do that anyway.
> 
> > Since reset_simple_reset() invokes
> > reset_simple_regmap_assert/deassert(), it also needs to be duplicated.
> 
> That one could go through the data->rcdev.ops->assert/deassert function
> pointers and be reused. But I wonder if that one function is worth the added
> complexity.
> 
> > In this case, there will be too many redundant codes in this file. I
> > doubt if it is worth to use the reset simple code. Maybe it's better
> > to fork a new file for the syscon device, such as 'reset-simple-syscon.c'. What
> do you say?
> 
> That sounds sensible to me.
> 

Well. I will go with the approach of a new driver, which avoids all the
unnecessary complexity and redundance. Thank!

> regards
> Philipp