mfd: fsl-imx25: Clean up irq settings during removal

commit 18f77393796848e68909e65d692c1d1436f06e06 upstream.

When fsl-imx25-tsadc is compiled as a module, loading, unloading and
reloading the module will lead to a crash.

Unable to handle kernel paging request at virtual address bf005430
[<c004df6c>] (irq_find_matching_fwspec)
   from [<c028d5ec>] (of_irq_get+0x58/0x74)
[<c028d594>] (of_irq_get)
   from [<c01ff970>] (platform_get_irq+0x48/0xc8)
[<c01ff928>] (platform_get_irq)
   from [<bf00e33c>] (mx25_tsadc_probe+0x220/0x2f4 [fsl_imx25_tsadc])

irq_find_matching_fwspec() loops over all registered irq domains. The
irq domain is still registered from last time the module was loaded but
the pointer to its operations is invalid after the module was unloaded.

Add a removal function which clears the irq handler and removes the irq
domain. With this cleanup in place, it's possible to unload and reload
the module.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mfd/fsl-imx25-tsadc.c b/drivers/mfd/fsl-imx25-tsadc.c
index b3767c3141e58a0fd9af028ced1ad13f67726c77..461b0990b56fcf5452cf0bb94cc08482a1c52e68 100644 (file)
--- a/drivers/mfd/fsl-imx25-tsadc.c
+++ b/drivers/mfd/fsl-imx25-tsadc.c
@@ -180,6 +180,19 @@ static int mx25_tsadc_probe(struct platform_device *pdev)
        return devm_of_platform_populate(dev);
 }
 
+static int mx25_tsadc_remove(struct platform_device *pdev)
+{
+       struct mx25_tsadc *tsadc = platform_get_drvdata(pdev);
+       int irq = platform_get_irq(pdev, 0);
+
+       if (irq) {
+               irq_set_chained_handler_and_data(irq, NULL, NULL);
+               irq_domain_remove(tsadc->domain);
+       }
+
+       return 0;
+}
+
 static const struct of_device_id mx25_tsadc_ids[] = {
        { .compatible = "fsl,imx25-tsadc" },
        { /* Sentinel */ }
@@ -192,6 +205,7 @@ static struct platform_driver mx25_tsadc_driver = {
                .of_match_table = of_match_ptr(mx25_tsadc_ids),
        },
        .probe = mx25_tsadc_probe,
+       .remove = mx25_tsadc_remove,
 };
 module_platform_driver(mx25_tsadc_driver);