Commit 730e5ebf authored by Danilo Krummrich's avatar Danilo Krummrich Committed by Bartosz Golaszewski
Browse files

gpio: omap: do not register driver in probe() 

Commit 11a78b79 ("ARM: OMAP: MPUIO wake updates") registers the
omap_mpuio_driver from omap_mpuio_init(), which is called from
omap_gpio_probe().

However, it neither makes sense to register drivers from probe()
callbacks of other drivers, nor does the driver core allow registering
drivers with a device lock already being held.

The latter was revealed by commit dc23806a ("driver core: enforce
device_lock for driver_match_device()") leading to a potential deadlock
condition described in [1].

Additionally, the omap_mpuio_driver is never unregistered from the
driver core, even if the module is unloaded.

Hence, register the omap_mpuio_driver from the module initcall and
unregister it in module_exit().

Link: https://lore.kernel.org/lkml/DFU7CEPUSG9A.1KKGVW4HIPMSH@kernel.org/

 [1]
Fixes: dc23806a ("driver core: enforce device_lock for driver_match_device()")
Fixes: 11a78b79 ("ARM: OMAP: MPUIO wake updates")
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarDanilo Krummrich <dakr@kernel.org>
Reviewed-by: default avatarRafael J. Wysocki (Intel) <rafael@kernel.org>
Link: https://patch.msgid.link/20260127201725.35883-1-dakr@kernel.org


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
parent d02f20a4

drivers/gpio/gpio-omap.c

+18 −4
Original line number Diff line number Diff line
@@ -799,10 +799,13 @@ static struct platform_device omap_mpuio_device = { 


static inline void omap_mpuio_init(struct gpio_bank *bank)

{

	platform_set_drvdata(&omap_mpuio_device, bank);

	static bool registered;



	if (platform_driver_register(&omap_mpuio_driver) == 0)

	platform_set_drvdata(&omap_mpuio_device, bank);

	if (!registered) {

		(void)platform_device_register(&omap_mpuio_device);

		registered = true;

	}

}



/*---------------------------------------------------------------------*/
@@ -1575,13 +1578,24 @@ static struct platform_driver omap_gpio_driver = { 
 */

static int __init omap_gpio_drv_reg(void)

{

	return platform_driver_register(&omap_gpio_driver);

	int ret;



	ret = platform_driver_register(&omap_mpuio_driver);

	if (ret)

		return ret;



	ret = platform_driver_register(&omap_gpio_driver);

	if (ret)

		platform_driver_unregister(&omap_mpuio_driver);



	return ret;

}

postcore_initcall(omap_gpio_drv_reg);



static void __exit omap_gpio_exit(void)

{

	platform_driver_unregister(&omap_gpio_driver);

	platform_driver_unregister(&omap_mpuio_driver);

}

module_exit(omap_gpio_exit);