[PATCH] spi: fsl-qspi: use devm function instead of driver remove

[Han Xu]

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>
---
 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;
+
 	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