[PATCH] mtd: rawnand: atmel: release the NFC IRQ before controller cleanup

[James Hilliard]

The NFC interrupt is shared and devm-managed. Controller removal disables
the clock used by the legacy binding before devres releases the handler.
An interrupt from another device on the shared line can therefore make
atmel_nfc_interrupt() read the NFC status with its clock disabled.

Release and drain the handler before freeing the controller resources.
Track successful IRQ registration because probe also uses this cleanup
path when requesting the IRQ itself fails.

Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
Cc: stable at vger.kernel.org
Signed-off-by: James Hilliard <james.hilliard1 at gmail.com>
---
 drivers/mtd/nand/raw/atmel/nand-controller.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c
index 0bdbcbb50d94..9a724de67624 100644
--- a/drivers/mtd/nand/raw/atmel/nand-controller.c
+++ b/drivers/mtd/nand/raw/atmel/nand-controller.c
@@ -263,6 +263,7 @@ struct atmel_hsmc_nand_controller {
 	struct completion complete;
 	u32 cfg;
 	int irq;
+	bool irq_requested;
 
 	/* Only used when instantiating from legacy DT bindings. */
 	struct clk *clk;
@@ -2334,6 +2335,9 @@ atmel_hsmc_nand_controller_remove(struct atmel_nand_controller *nc)
 	regmap_write(hsmc_nc->base.smc, ATMEL_HSMC_NFC_CTRL,
 		     ATMEL_HSMC_NFC_CTRL_DIS);
 
+	if (hsmc_nc->irq_requested)
+		devm_free_irq(nc->dev, hsmc_nc->irq, hsmc_nc);
+
 	if (hsmc_nc->sram.pool)
 		gen_pool_free(hsmc_nc->sram.pool,
 			      (unsigned long)hsmc_nc->sram.virt,
@@ -2383,6 +2387,8 @@ static int atmel_hsmc_nand_controller_probe(struct platform_device *pdev,
 		goto err;
 	}
 
+	nc->irq_requested = true;
+
 	/* Initial NFC configuration. */
 	regmap_write(nc->base.smc, ATMEL_HSMC_NFC_CFG,
 		     ATMEL_HSMC_NFC_CFG_DTO_MAX);

---
base-commit: 30daaf3e7897b4a8d9b72e5b0c86dd6e2a4d7d85
change-id: 20261107-submit-atmel-nand-irq-teardown-v1-f902307c18db

Best regards,
--  
James Hilliard <james.hilliard1 at gmail.com>