linux-kernel - Re: [PATCH] peci: aspeed: Clear clock

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Date: Wed, 12 Jun 2024 02:23:59 +0000
From: Billy Tsai <billy_tsai@...eedtech.com>
To: Andrew Jeffery <andrew@...econstruct.com.au>, "Winiarska, Iwona"
	<iwona.winiarska@...el.com>, "linux-aspeed@...ts.ozlabs.org"
	<linux-aspeed@...ts.ozlabs.org>, "linux-arm-kernel@...ts.infradead.org"
	<linux-arm-kernel@...ts.infradead.org>, "openbmc@...ts.ozlabs.org"
	<openbmc@...ts.ozlabs.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] peci: aspeed: Clear clock_divider value before setting it

> On Thu, 2024-04-18 at 13:41 +0000, Winiarska, Iwona wrote:
> > On Thu, 2024-04-18 at 09:11 +0930, Andrew Jeffery wrote:
> > > Hi Iwona,
> > >
> > > On Wed, 2024-04-17 at 15:48 +0200, Iwona Winiarska wrote:
> > > > PECI clock divider is programmed on 10:8 bits of PECI Control register.
> > > > Before setting a new value, clear bits read from hardware.
> > > >
> > > > Signed-off-by: Iwona Winiarska <iwona.winiarska@...el.com>
> > >
> > > I think it would be best to add a Fixes: tag and Cc: stable in
> > > accordance with the stable tree rules. Are you happy to do so?
> >
> > Hi!
> >
> > Technically, the initial value of this register should be 0, but I've added the
> > clear just to be on the safe side and to not have to rely on that.

> Yeah, it could cause havoc with an unbind/bind sequence if people are
> messing with the clocks in between.

> > I don't think we're ever programming invalid values in the real-world scenarios,
> > and because of that - I don't think this is stable material.

> Right, I don't expect people are doing the above in environments where
> stability is a concern.

Reviewed-by: Billy Tsai <billy_tsai@...eedtech.com>

Billy