linux-kernel - Re: [PATCH 4/5] clk: Add flag to prevent frequency changes when walking subtrees

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Message-ID: <3bcf5bc1007c9ed2900780fe07e66cb8.sboyd@kernel.org>
Date: Mon, 30 Dec 2024 17:09:32 -0800
From: Stephen Boyd <sboyd@...nel.org>
To: Miquel Raynal <miquel.raynal@...tlin.com>
Cc: Abel Vesa <abelvesa@...nel.org>, Fabio Estevam <festevam@...il.com>, Marek Vasut <marex@...x.de>, Michael Turquette <mturquette@...libre.com>, Peng Fan <peng.fan@....com>, Pengutronix Kernel Team <kernel@...gutronix.de>, Sascha Hauer <s.hauer@...gutronix.de>, Shawn Guo <shawnguo@...nel.org>, Ying Liu <victor.liu@....com>, Laurent Pinchart <laurent.pinchart@...asonboard.com>, linux-clk@...r.kernel.org, imx@...ts.linux.dev, linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org, Abel Vesa <abel.vesa@...aro.org>, Herve Codina <herve.codina@...tlin.com>, Luca Ceresoli <luca.ceresoli@...tlin.com>, Thomas Petazzoni <thomas.petazzoni@...tlin.com>, Ian Ray <ian.ray@...com>
Subject: Re: [PATCH 4/5] clk: Add flag to prevent frequency changes when walking subtrees

Quoting Miquel Raynal (2024-12-23 10:38:20)
> Hi Stephen,
> 
> >> +/* do not passively change this clock rate during subtree rate propagation */
> >> +#define CLK_NO_RATE_CHANGE_DURING_PROPAGATION BIT(14)
> >
> > Why doesn't rate locking work?
> 
> Can you be more specific? What function from the API is supposed to do
> what I need? AFAIU, none of them is properly locking the rate during a
> subtree walk, but if I misread one of them, I'd be glad to drop all this.
> 

It's clk_set_rate_exclusive() as Maxime also asked about in the other
thread.