linux-kernel - Re: [PATCH 2/4] pwm: stm32-lp: Add power management support

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: <20190206085405.pdiwd3c6wjog5hl7@pengutronix.de>
Date:   Wed, 6 Feb 2019 09:54:05 +0100
From:   Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>
To:     Fabrice Gasnier <fabrice.gasnier@...com>
Cc:     Thierry Reding <thierry.reding@...il.com>, jic23@...nel.org,
        robh+dt@...nel.org, mark.rutland@....com, alexandre.torgue@...com,
        mcoquelin.stm32@...il.com, linux-iio@...r.kernel.org,
        devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, linux-pwm@...r.kernel.org,
        vilhelm.gray@...il.com, linux-stm32@...md-mailman.stormreply.com,
        Tomasz Duszynski <tduszyns@...il.com>
Subject: Re: [PATCH 2/4] pwm: stm32-lp: Add power management support

On Wed, Feb 06, 2019 at 09:42:48AM +0100, Fabrice Gasnier wrote:
> If you agree with the current approach, I can send a V2 with Tomasz's
> suggestion to remove the ifdefs and use __maybe_unused instead.

I think the suspend callback should have something like:

	if (is_still_enabled) {
		/*
		 * The consumer didn't stop us, so refuse to suspend.
		 */
		dev_err(dev, "The consumer didn't stop us, so refuse to suspend.\n");
		return -EBUSY;
	}

This way there are no bad surprises if the pwm is suspended before its
consumer and it's obvious what is missing.

Best regards
Uwe

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