linux-kernel - Re: [PATCH] spi: imx: Revert "spi: imx: enable runtime pm support"

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Message-ID: <20201009073944.GA11648@pengutronix.de>
Date:   Fri, 9 Oct 2020 09:39:44 +0200
From:   Sascha Hauer <s.hauer@...gutronix.de>
To:     Christian Eggers <ceggers@...i.de>
Cc:     Mark Brown <broonie@...nel.org>, Shawn Guo <shawnguo@...nel.org>,
        Pengutronix Kernel Team <kernel@...gutronix.de>,
        Fabio Estevam <festevam@...il.com>,
        NXP Linux Team <linux-imx@....com>,
        linux-spi@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] spi: imx: Revert "spi: imx: enable runtime pm support"

On Fri, Oct 09, 2020 at 06:27:38AM +0200, Christian Eggers wrote:
> This reverts commit 525c9e5a32bd7951eae3f06d9d077fea51718a6c.
> 
> If CONFIG_PM is disabled, the system completely freezes on probe as
> nothing enables the clock of the SPI peripheral.

Instead of reverting it, why not just fix it?

Normally the device should be brought to active state manually in probe
before pm_runtime takes over, then CONFIG_PM disabled doesn't hurt.
Using pm_runtime to put the device to active state initially has the
problem you describe.

Sascha


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