From: Sean Anderson <sean.anderson@seco.com>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: linux-pwm@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, michal.simek@xilinx.com,
Lee Jones <lee.jones@linaro.org>,
Thierry Reding <thierry.reding@gmail.com>
Subject: Re: [PATCH 2/2] pwm: Add support for Xilinx AXI Timer
Date: Tue, 4 May 2021 11:03:34 -0400 [thread overview]
Message-ID: <70fa97ba-ea32-e734-acd5-5f5de3c03348@seco.com> (raw)
In-Reply-To: <2ef7de6f-4d17-e81a-11bc-27eb382577a7@seco.com>
On 5/4/21 10:46 AM, Sean Anderson wrote:
> On 5/4/21 4:51 AM, Uwe Kleine-König wrote:
> >> +static int xilinx_pwm_remove(struct platform_device *pdev)
> >> +{
> >> + struct xilinx_pwm_device *pwm = platform_get_drvdata(pdev);
> >> + bool enabled = xilinx_pwm_is_enabled(readl(pwm->regs + TCSR0),
> >> + readl(pwm->regs + TCSR1));
> >> +
> >> + if (enabled)
> >> + clk_rate_exclusive_put(pwm->clk);
> >
> > This looks wrong. You should rely on the consumer that they disable the
> > PWM.
>
> What about a PWM regulator with always-on?
>
> This is mostly to match the exclusive_get in probe, in case there are
> misbehaving consumers.
Since we always get the rate exclusively, we must always put the rate
exclusively here. So if the PWM is probed, but no one ever does anything
with it (and therefore no one turns it off), we must release the
exclusive rate in remove.
--Sean
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next prev parent reply other threads:[~2021-05-04 15:06 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-03 21:44 [PATCH 1/2] dt-bindings: pwm: Add Xilinx AXI Timer Sean Anderson
2021-05-03 21:44 ` [PATCH 2/2] pwm: Add support for " Sean Anderson
2021-05-04 2:24 ` kernel test robot
2021-05-04 9:03 ` Alvaro Gamez
2021-05-04 17:16 ` Sean Anderson
2021-05-04 8:51 ` Uwe Kleine-König
2021-05-04 12:32 ` Michal Simek
2021-05-04 15:57 ` Sean Anderson
2021-05-04 16:13 ` Uwe Kleine-König
2021-05-05 6:31 ` Michal Simek
2021-05-04 14:46 ` Sean Anderson
2021-05-04 15:03 ` Sean Anderson [this message]
2021-05-04 17:15 ` Uwe Kleine-König
2021-05-04 18:01 ` Sean Anderson
2021-05-04 0:21 ` [PATCH 1/2] dt-bindings: pwm: Add " Rob Herring
2021-05-04 14:51 ` Sean Anderson
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