Re: [PATCH] spi: fsl-qspi: use devm function instead of driver remove
From: Frank Li
Date: Thu Mar 27 2025 - 11:45:45 EST
On Wed, Mar 26, 2025 at 05:41:51PM -0500, Han Xu wrote:
> Driver use devm APIs to manage clk/irq/resources and register the spi
> controller, but the legacy remove function will be called first during
> device detach and trigger kernel panic. Drop the remove function and use
> devm_add_action_or_reset() for driver cleanup to ensure the release
> sequence.
>
> Trigger kernel panic on i.MX8MQ by
> echo 30bb0000.spi >/sys/bus/platform/drivers/fsl-quadspi/unbind
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 8fcb830a00f0 ("spi: spi-fsl-qspi: use devm_spi_register_controller")
> Reported-by: Kevin Hao <haokexin@xxxxxxxxx>
> Signed-off-by: Han Xu <han.xu@xxxxxxx>
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
> ---
> drivers/spi/spi-fsl-qspi.c | 31 +++++++++++++++++--------------
> 1 file changed, 17 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/spi/spi-fsl-qspi.c b/drivers/spi/spi-fsl-qspi.c
> index 355e6a39fb418..5c59fddb32c1b 100644
> --- a/drivers/spi/spi-fsl-qspi.c
> +++ b/drivers/spi/spi-fsl-qspi.c
> @@ -844,6 +844,19 @@ static const struct spi_controller_mem_caps fsl_qspi_mem_caps = {
> .per_op_freq = true,
> };
>
> +static void fsl_qspi_cleanup(void *data)
> +{
> + struct fsl_qspi *q = data;
> +
> + /* disable the hardware */
> + qspi_writel(q, QUADSPI_MCR_MDIS_MASK, q->iobase + QUADSPI_MCR);
> + qspi_writel(q, 0x0, q->iobase + QUADSPI_RSER);
> +
> + fsl_qspi_clk_disable_unprep(q);
> +
> + mutex_destroy(&q->lock);
> +}
> +
> static int fsl_qspi_probe(struct platform_device *pdev)
> {
> struct spi_controller *ctlr;
> @@ -934,6 +947,10 @@ static int fsl_qspi_probe(struct platform_device *pdev)
>
> ctlr->dev.of_node = np;
>
> + ret = devm_add_action_or_reset(dev, fsl_qspi_cleanup, q);
> + if (ret)
> + goto err_destroy_mutex;
> +
Look like needn't goto err_destroy_mutex. it should be enough
if (ret)
return ret;
Orginal error path:
err_destroy_mutex:
mutex_destroy(&q->lock); // already in fsl_qspi_cleanup()
err_disable_clk:
fsl_qspi_clk_disable_unprep(q); // already in fsl_qspi_cleanup()
err_put_ctrl:
spi_controller_put(ctlr); // suppose it is wrong, devm_spi_register_controller()
should consider it.
Frank
> ret = devm_spi_register_controller(dev, ctlr);
> if (ret)
> goto err_destroy_mutex;
> @@ -953,19 +970,6 @@ static int fsl_qspi_probe(struct platform_device *pdev)
> return ret;
> }
>
> -static void fsl_qspi_remove(struct platform_device *pdev)
> -{
> - struct fsl_qspi *q = platform_get_drvdata(pdev);
> -
> - /* disable the hardware */
> - qspi_writel(q, QUADSPI_MCR_MDIS_MASK, q->iobase + QUADSPI_MCR);
> - qspi_writel(q, 0x0, q->iobase + QUADSPI_RSER);
> -
> - fsl_qspi_clk_disable_unprep(q);
> -
> - mutex_destroy(&q->lock);
> -}
> -
> static int fsl_qspi_suspend(struct device *dev)
> {
> return 0;
> @@ -1003,7 +1007,6 @@ static struct platform_driver fsl_qspi_driver = {
> .pm = &fsl_qspi_pm_ops,
> },
> .probe = fsl_qspi_probe,
> - .remove = fsl_qspi_remove,
> };
> module_platform_driver(fsl_qspi_driver);
>
> --
> 2.34.1
>