linux-kernel - Re: [PATCH 03/10] spi: spi-mem: Add driver for Aspeed SMC controllers

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Message-ID: <20220215062743.GA12431@wunner.de>
Date:   Tue, 15 Feb 2022 07:27:43 +0100
From:   Lukas Wunner <lukas@...ner.de>
To:     Cédric Le Goater <clg@...d.org>
Cc:     linux-spi@...r.kernel.org, linux-mtd@...ts.infradead.org,
        Mark Brown <broonie@...nel.org>,
        Tudor Ambarus <tudor.ambarus@...rochip.com>,
        Pratyush Yadav <p.yadav@...com>,
        Miquel Raynal <miquel.raynal@...tlin.com>,
        Richard Weinberger <richard@....at>,
        Vignesh Raghavendra <vigneshr@...com>,
        linux-aspeed@...ts.ozlabs.org, Joel Stanley <joel@....id.au>,
        Andrew Jeffery <andrew@...id.au>,
        Chin-Ting Kuo <chin-ting_kuo@...eedtech.com>,
        devicetree@...r.kernel.org, Rob Herring <robh+dt@...nel.org>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 03/10] spi: spi-mem: Add driver for Aspeed SMC controllers

On Mon, Feb 14, 2022 at 10:42:24AM +0100, Cédric Le Goater wrote:
> +static int aspeed_spi_probe(struct platform_device *pdev)
> +{
[...]
> +	ctlr = spi_alloc_master(dev, sizeof(*aspi));
> +	if (!ctlr)
> +		return -ENOMEM;

Use devm_spi_alloc_master() and remove the "put_controller" error path
for simplicity.


> +	ret = devm_spi_register_controller(dev, ctlr);
[...]
> +static int aspeed_spi_remove(struct platform_device *pdev)
> +{
> +	struct spi_controller *ctlr = platform_get_drvdata(pdev);
> +	struct aspeed_spi *aspi = spi_controller_get_devdata(ctlr);
> +
> +	aspeed_spi_enable(aspi, false);
> +	spi_unregister_controller(ctlr);
> +	clk_disable_unprepare(aspi->clk);
> +	return 0;
> +}

You need to move the call to spi_unregister_controller() *before*
the call to aspeed_spi_enable().  The controller must be fully
operational until spi_unregister_controller() returns.

You also need to replace the call to devm_spi_register_controller()
in aspeed_spi_probe() with spi_register_controller().
Otherwise you'll unregister the controller twice because you're
calling spi_unregister_controller() in aspeed_spi_remove().

Thanks,

Lukas