Commit 1e185c7a authored Aug 08, 2013 by Mike Dunn Committed by Thierry Reding Sep 03, 2013

pwm: pxa: Use module_platform_driver



Commit 76abbdde

    pwm: Add sysfs interface

causes a kernel oops due to a null pointer dereference on PXA platforms.
This happens because the class added by the patch is registered in a
subsys_initcall (initcall4), but the pxa pwm driver is registered in
arch_initcall (initcall3). If the class is not registered before the
driver probe function runs, the oops occurs in device_add() when the
uninitialized pointers in struct class are dereferenced.  I don't see a
reason that the driver must be an arch_initcall, so this patch makes it
a regular module_platform_driver (initcall6), preventing the oops.

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

parent ac872bc9

drivers/pwm/pwm-pxa.c

+1 −11

Original line number	Diff line number	Diff line
		@@ -182,16 +182,6 @@ static struct platform_driver pwm_driver = {
		.id_table = pwm_id_table,
		};

		static int __init pwm_init(void)
		{
		return platform_driver_register(&pwm_driver);
		}
		arch_initcall(pwm_init);

		static void __exit pwm_exit(void)
		{
		platform_driver_unregister(&pwm_driver);
		}
		module_exit(pwm_exit);
		module_platform_driver(pwm_driver);

		MODULE_LICENSE("GPL v2");

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