linux-kernel - RE: [PATCH V2] clk: scmi: add is

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:
 <PAXPR04MB845938597DBD50DE1D1C0A1088B22@PAXPR04MB8459.eurprd04.prod.outlook.com>
Date: Thu, 1 Aug 2024 03:35:37 +0000
From: Peng Fan <peng.fan@....com>
To: Sudeep Holla <sudeep.holla@....com>, Dhruva Gole <d-gole@...com>
CC: "Peng Fan (OSS)" <peng.fan@....nxp.com>, "cristian.marussi@....com"
	<cristian.marussi@....com>, "mturquette@...libre.com"
	<mturquette@...libre.com>, "sboyd@...nel.org" <sboyd@...nel.org>,
	"linux-clk@...r.kernel.org" <linux-clk@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org"
	<linux-arm-kernel@...ts.infradead.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, "arm-scmi@...r.kernel.org"
	<arm-scmi@...r.kernel.org>
Subject: RE: [PATCH V2] clk: scmi: add is_prepared hook

Hi Sudeep, Dhruva,

> Subject: Re: [PATCH V2] clk: scmi: add is_prepared hook
> 
> On Fri, Jul 26, 2024 at 07:22:31PM +0530, Dhruva Gole wrote:
> > On Jul 26, 2024 at 21:10:07 +0800, Peng Fan (OSS) wrote:
> > > From: Peng Fan <peng.fan@....com>
> > >
> > > Some clks maybe default enabled by hardware, so add is_prepared
> hook
> > > for non-atomic clk_ops to get the status of the clk. Then when
> > > disabling unused clks, those unused clks but default hardware on
> > > clks could be in off state to save power.
> >
> > Just a nit - reword the commit message as:
> > Then when disabling the unused clocks, they can be simply turned
> OFF
> > to save power.
> >
> 
> Ah this was what it meant. I couldn't parse the original text and was
> about to ask.
> 
> > Also if you can make it still verbose, explain when you expect this
> > disabling of unused clks to take place exactly? During boot?  Driver
> probe sequence?
> > or By some user commands?
> >
> 
> Agreed. Being little more verbose here would be beneficial IMO.
> 

I will use below in V3:
"
Some clocks maybe default enabled by hardwar. For clocks that not 
have users, they will be left in hardware default state, because prepare
count and enable count is zero,if there is no is_prepared hook to get
the hardware state. So add is_prepared hook to detect the hardware
state. Then when disabling the unused clocks, they can be simply
turned OFF to save power during kernel boot.
"

I will post out v3 in later next week, waiting to see any more comments.

Thanks,
Peng.

> --
> Regards,
> Sudeep