Re: [PATCH] ARM: sa1100: Initialize gpio after gpio subsystem has been initialized

From: Guenter Roeck
Date: Thu Mar 31 2016 - 12:21:19 EST


On Tue, Mar 29, 2016 at 11:15:49AM -0700, Guenter Roeck wrote:
> The sa1100 gpio driver was initialized from interrupt initialization code,
> which is earlier than the gpio subsystem is initialized. Since commit
> ff2b13592299 ("gpio: make the gpiochip a real device"), this is fatal
> and causes the system to crash.
>
> The sa1100 gpio driver must be initialized prior to arch_initcall, since
> its gpio pins are used in arch_initcall code, but after the gpio subsystem
> is initialized (core_initcall). Initialize it with postcore_initcall.
>
> Fixes: ff2b13592299 ("gpio: make the gpiochip a real device")
> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Please ignore/drop this patch - a better (cleaner) fix is in the works
for gpiolib.

Thanks,
Guenter

> ---
>
> Tested by building collie_defconfig and:
>
> qemu-system-arm -M collie -kernel arch/arm/boot/zImage \
> -no-reboot -initrd busybox-armv4.cpio \
> --append "rdinit=/sbin/init console=ttySA1" -monitor null -nographic
>
> arch/arm/mach-sa1100/generic.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/mach-sa1100/generic.c b/arch/arm/mach-sa1100/generic.c
> index 345e63f4eb71..850aa7f8f649 100644
> --- a/arch/arm/mach-sa1100/generic.c
> +++ b/arch/arm/mach-sa1100/generic.c
> @@ -321,6 +321,15 @@ static int __init sa1100_init(void)
>
> arch_initcall(sa1100_init);
>
> +static int __init sa1100_gpio_init(void)
> +{
> + sa1100_init_gpio();
> +
> + return 0;
> +}
> +
> +postcore_initcall(sa1100_gpio_init);
> +
> void __init sa11x0_init_late(void)
> {
> sa11x0_pm_init();
> @@ -386,8 +395,6 @@ void __init sa1100_init_irq(void)
> request_resource(&iomem_resource, &irq_resource);
>
> sa11x0_init_irq_nodt(IRQ_GPIO0_SC, irq_resource.start);
> -
> - sa1100_init_gpio();
> }
>
> /*
> --
> 2.5.0
>