[tip: irq/drivers] irqchip/imx-intmux: Fix runtime PM teardown on remove

[tip-bot2 for Guangshuo Li]

The following commit has been merged into the irq/drivers branch of tip:

Commit-ID:     b167c1a30e9e020e4c5e102c7a555943742c024b
Gitweb:        https://git.kernel.org/tip/b167c1a30e9e020e4c5e102c7a555943742c024b
Author:        Guangshuo Li <lgs201920130244@xxxxxxxxx>
AuthorDate:    Mon, 14 Sep 2026 21:42:11 +08:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxx>
CommitterDate: Thu, 15 Oct 2026 11:50:47 +02:00

irqchip/imx-intmux: Fix runtime PM teardown on remove

imx_intmux_probe() enables the IPG clock and then drops its runtime PM
reference with pm_runtime_put(). With CONFIG_PM enabled, the runtime
suspend callback disables the IPG clock. With CONFIG_PM disabled, the
clock remains enabled after probe.

imx_intmux_remove() accesses the CHANIER registers without first making
sure that the device is runtime active. The device may therefore be
runtime suspended with the IPG clock disabled when these registers are
accessed. In addition, the remove path only calls pm_runtime_disable()
and does not balance the clock enable when CONFIG_PM is disabled.

Resume the device and acquire a runtime PM reference before accessing
the registers. If resume fails, skip the register accesses but still
tear down the chained handlers and IRQ domains. Disable runtime PM
afterwards, drop the acquired reference without triggering another
runtime suspend, and explicitly disable the IPG clock.

This keeps the clock enabled while the hardware registers are accessed
and balances the clk_prepare_enable() performed during probe for both
CONFIG_PM configurations.

This issue was found by manual code inspection.

Fixes: bb403111e017 ("irqchip/imx-intmux: Implement intmux runtime power management")
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxx>
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
Reviewed-by: Radu Rendec <radu@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://patch.msgid.link/20260914134211.1734163-1-lgs201920130244@xxxxxxxxx
---
 drivers/irqchip/irq-imx-intmux.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-imx-intmux.c b/drivers/irqchip/irq-imx-intmux.c
index 47c2681..de2a8f9 100644
--- a/drivers/irqchip/irq-imx-intmux.c
+++ b/drivers/irqchip/irq-imx-intmux.c
@@ -288,12 +288,16 @@ out:
 static void imx_intmux_remove(struct platform_device *pdev)
 {
 	struct intmux_data *data = platform_get_drvdata(pdev);
-	int i;
+	int i, ret;
+
+	ret = pm_runtime_resume_and_get(&pdev->dev);
+	if (ret < 0)
+		dev_warn(&pdev->dev, "failed to resume device: %d\n", ret);
 
 	for (i = 0; i < data->channum; i++) {
 		/* disable all interrupt sources of this channel */
-		writel_relaxed(0, data->regs + CHANIER(i));
-
+		if (ret >= 0)
+			writel_relaxed(0, data->regs + CHANIER(i));
 		irq_set_chained_handler_and_data(data->irqchip_data[i].irq,
 						 NULL, NULL);
 
@@ -301,6 +305,11 @@ static void imx_intmux_remove(struct platform_device *pdev)
 	}
 
 	pm_runtime_disable(&pdev->dev);
+	if (ret >= 0) {
+		pm_runtime_put_noidle(&pdev->dev);
+		clk_disable_unprepare(data->ipg_clk);
+		pm_runtime_set_suspended(&pdev->dev);
+	}
 }
 
 #ifdef CONFIG_PM