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

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

[Guenter Roeck]

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@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---

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

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

[Guenter Roeck]

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@linaro.org>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

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
> 

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

[Linus Walleij]

On Thu, Mar 31, 2016 at 6:21 PM, Guenter Roeck <linux@roeck-us.net> wrote:
> 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@linaro.org>
>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>
> Please ignore/drop this patch - a better (cleaner) fix is in the works
> for gpiolib.

This delivers though. I tested it on my also regressing iPAQ.

Yours,
Linus Walleij

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

[Guenter Roeck]

On Fri, Apr 01, 2016 at 10:04:57AM +0200, Linus Walleij wrote:
> On Thu, Mar 31, 2016 at 6:21 PM, Guenter Roeck <linux@roeck-us.net> wrote:
> > 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@linaro.org>
> >> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> >
> > Please ignore/drop this patch - a better (cleaner) fix is in the works
> > for gpiolib.
> 
> This delivers though. I tested it on my also regressing iPAQ.
> 
I am a bit concerned that the gpio initialization was that early on purpose,
and that by moving it we might miss some use cases. I did not find any, but that
doesn't mean that there are none. Without knowing _why_ the initialization was
that early, I would prefer not to touch the code if it can be avoided.

Thanks,
Guenter

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

[Linus Walleij]

On Fri, Apr 1, 2016 at 4:02 PM, Guenter Roeck <linux@roeck-us.net> wrote:
> On Fri, Apr 01, 2016 at 10:04:57AM +0200, Linus Walleij wrote:

>> > Please ignore/drop this patch - a better (cleaner) fix is in the works
>> > for gpiolib.
>>
>> This delivers though. I tested it on my also regressing iPAQ.
>>
> I am a bit concerned that the gpio initialization was that early on purpose,
> and that by moving it we might miss some use cases. I did not find any, but that
> doesn't mean that there are none. Without knowing _why_ the initialization was
> that early, I would prefer not to touch the code if it can be avoided.

I think we'll go for the other patch to gpiolib. It seems much more clean
and generic to support this kind of cases.

Yours,
Linus Walleij