Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 23 Sep 2019 11:17:45 +0200
From:   Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= 
        <u.kleine-koenig@pengutronix.de>
To:     Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Russell King <linux@armlinux.org.uk>
Cc:     Thierry Reding <thierry.reding@gmail.com>,
        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Fabio Estevam <festevam@gmail.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        devicetree@vger.kernel.org, linux-pwm@vger.kernel.org,
        linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
        linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org
Subject: Re: [PATCH 1/4] pwm: mxs: implement ->apply
Message-ID: <20190923091745.ehvz4zi2riyanmug@pengutronix.de>
References: <20190923081348.6843-1-linux@rasmusvillemoes.dk>
 <20190923081348.6843-2-linux@rasmusvillemoes.dk>
 <20190923082459.huqpbz5eseonkscv@pengutronix.de>
 <a6407644-0b5b-ba46-9435-0d14be9066a5@rasmusvillemoes.dk>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <a6407644-0b5b-ba46-9435-0d14be9066a5@rasmusvillemoes.dk>
User-Agent: NeoMutt/20170113 (1.7.2)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hello,

[expanded the recipents to include RMK and the clk list]

On Mon, Sep 23, 2019 at 11:04:39AM +0200, Rasmus Villemoes wrote:
> On 23/09/2019 10.24, Uwe Kleine-K?nig wrote:
> > Also there is a bug already in .config: You are not supposed to call
> > clk_get_rate if the clk might be off.
> 
> Interesting, I didn't know that. So the prepare_enable logic needs to be
> moved before we start computing the period/duty cycles. Do you know why
> it has apparently worked so far? I would have thought such a rule would
> be enforced by the clock framework, or at least produced a warning.

FTR: This is documented in the kerneldoc code comment to clk_get_rate in
include/linux/clk.h.

Assuming this is relevant, it might indeed make sense to add a
WARN_ONCE for this.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-K?nig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |