4.9-stable review patch. If anyone has any objections, please let me know.
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From: Martin Kaiser martin@kaiser.cx
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
--- drivers/mfd/fsl-imx25-tsadc.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
--- a/drivers/mfd/fsl-imx25-tsadc.c +++ b/drivers/mfd/fsl-imx25-tsadc.c @@ -183,6 +183,19 @@ static int mx25_tsadc_probe(struct platf return 0; }
+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 */ } @@ -194,6 +207,7 @@ static struct platform_driver mx25_tsadc .of_match_table = of_match_ptr(mx25_tsadc_ids), }, .probe = mx25_tsadc_probe, + .remove = mx25_tsadc_remove, }; module_platform_driver(mx25_tsadc_driver);