[PATCH 1/4] gpio: remove broken irq_to_gpio() interface

[PATCH 1/4] gpio: remove broken irq_to_gpio() interface

[Arnd Bergmann]

gpiolib has removed the irq_to_gpio() API several years ago,
but the global header still provided a non-working stub.

Apparently one new user has shown up in arch/mips, so this patch
moves the broken definition to where it is used, ensuring that
we get new users but not changing the current behavior on jz4740.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/mips/jz4740/gpio.c |  7 +++++++
 include/linux/gpio.h    | 12 ------------
 2 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/arch/mips/jz4740/gpio.c b/arch/mips/jz4740/gpio.c
index 8c6d76c9b2d6..e9bb43714892 100644
--- a/arch/mips/jz4740/gpio.c
+++ b/arch/mips/jz4740/gpio.c
@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/compiler.h>
 
 #include <linux/io.h>
 #include <linux/gpio.h>
@@ -270,6 +271,12 @@ uint32_t jz_gpio_port_get_value(int port, uint32_t mask)
 }
 EXPORT_SYMBOL(jz_gpio_port_get_value);
 
+static inline __deprecated int irq_to_gpio(unsigned int irq)
+{
+	/* this has clearly not worked for a long time */
+	return -EINVAL;
+}
+
 #define IRQ_TO_BIT(irq) BIT(irq_to_gpio(irq) & 0x1f)
 
 static void jz_gpio_check_trigger_both(struct jz_gpio_chip *chip, unsigned int irq)
diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index d12b5d566e4b..6fc1c9e74854 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -70,11 +70,6 @@ static inline int gpio_to_irq(unsigned int gpio)
 	return __gpio_to_irq(gpio);
 }
 
-static inline int irq_to_gpio(unsigned int irq)
-{
-	return -EINVAL;
-}
-
 #endif /* ! CONFIG_ARCH_HAVE_CUSTOM_GPIO_H */
 
 /* CONFIG_GPIOLIB: bindings for managed devices that want to request gpios */
@@ -222,13 +217,6 @@ static inline void gpiochip_unlock_as_irq(struct gpio_chip *chip,
 	WARN_ON(1);
 }
 
-static inline int irq_to_gpio(unsigned irq)
-{
-	/* irq can never have been returned from gpio_to_irq() */
-	WARN_ON(1);
-	return -EINVAL;
-}
-
 static inline int
 gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 		       unsigned int gpio_offset, unsigned int pin_offset,
-- 
2.7.0

Re: [PATCH 1/4] gpio: remove broken irq_to_gpio() interface

[Lars-Peter Clausen]

On 02/15/2016 04:46 PM, Arnd Bergmann wrote:
> +static inline __deprecated int irq_to_gpio(unsigned int irq)
> +{
> +	/* this has clearly not worked for a long time */
> +	return -EINVAL;
> +}
> +
>  #define IRQ_TO_BIT(irq) BIT(irq_to_gpio(irq) & 0x1f)

The issue seems to be a fallout from commit 832f5dacfa0b ("MIPS: Remove all
the uses of custom gpio.h").

The irq_to_gpio() should be replaced with "(irq - JZ4740_IRQ_GPIO(0))".

- Lars

Re: [PATCH 1/4] gpio: remove broken irq_to_gpio() interface

[Arnd Bergmann]

On Monday 15 February 2016 17:01:09 Lars-Peter Clausen wrote:
> On 02/15/2016 04:46 PM, Arnd Bergmann wrote:
> > +static inline __deprecated int irq_to_gpio(unsigned int irq)
> > +{
> > +     /* this has clearly not worked for a long time */
> > +     return -EINVAL;
> > +}
> > +
> >  #define IRQ_TO_BIT(irq) BIT(irq_to_gpio(irq) & 0x1f)
> 
> The issue seems to be a fallout from commit 832f5dacfa0b ("MIPS: Remove all
> the uses of custom gpio.h").
> 
> The irq_to_gpio() should be replaced with "(irq - JZ4740_IRQ_GPIO(0))".
> 
> 

Ah, that explain it, so it has not been broken for that long.

	Arnd

Re: [PATCH 1/4] gpio: remove broken irq_to_gpio() interface

[Linus Walleij]

On Mon, Feb 15, 2016 at 4:46 PM, Arnd Bergmann <arnd@arndb.de> wrote:

> gpiolib has removed the irq_to_gpio() API several years ago,
> but the global header still provided a non-working stub.
>
> Apparently one new user has shown up in arch/mips, so this patch
> moves the broken definition to where it is used, ensuring that
> we get new users but not changing the current behavior on jz4740.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Patch applied.

I expect the driver maintainer to deal with the resulting
deprecation fallout.

Yours,
Linus Walleij

Re: [PATCH 1/4] gpio: remove broken irq_to_gpio() interface

[Linus Walleij]

On Mon, Feb 15, 2016 at 4:46 PM, Arnd Bergmann <arnd@arndb.de> wrote:

> gpiolib has removed the irq_to_gpio() API several years ago,
> but the global header still provided a non-working stub.
>
> Apparently one new user has shown up in arch/mips, so this patch
> moves the broken definition to where it is used, ensuring that
> we get new users but not changing the current behavior on jz4740.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Patch applied.

I expect the driver maintainer to deal with the resulting
deprecation fallout.

Yours,
Linus Walleij

Re: [PATCH 1/4] gpio: remove broken irq_to_gpio() interface

[Arnd Bergmann]

On Tuesday 16 February 2016 16:42:18 Linus Walleij wrote:
> On Mon, Feb 15, 2016 at 4:46 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> 
> > gpiolib has removed the irq_to_gpio() API several years ago,
> > but the global header still provided a non-working stub.
> >
> > Apparently one new user has shown up in arch/mips, so this patch
> > moves the broken definition to where it is used, ensuring that
> > we get new users but not changing the current behavior on jz4740.
> >
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> 
> Patch applied.
> 
> I expect the driver maintainer to deal with the resulting
> deprecation fallout.
> 

I've just sent v2 of the series, with a separate patch for MIPS
that now conflicts with this one. Can you pick up the new patch
instead?

	Arnd

Re: [PATCH 1/4] gpio: remove broken irq_to_gpio() interface

[Arnd Bergmann]

On Tuesday 16 February 2016 16:42:18 Linus Walleij wrote:
> On Mon, Feb 15, 2016 at 4:46 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> 
> > gpiolib has removed the irq_to_gpio() API several years ago,
> > but the global header still provided a non-working stub.
> >
> > Apparently one new user has shown up in arch/mips, so this patch
> > moves the broken definition to where it is used, ensuring that
> > we get new users but not changing the current behavior on jz4740.
> >
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> 
> Patch applied.
> 
> I expect the driver maintainer to deal with the resulting
> deprecation fallout.
> 

I've just sent v2 of the series, with a separate patch for MIPS
that now conflicts with this one. Can you pick up the new patch
instead?

	Arnd

Re: [PATCH 1/4] gpio: remove broken irq_to_gpio() interface

[Linus Walleij]

On Tue, Feb 16, 2016 at 4:45 PM, Arnd Bergmann <arnd@arndb.de> wrote:

> I've just sent v2 of the series, with a separate patch for MIPS
> that now conflicts with this one. Can you pick up the new patch
> instead?

OK I'll back out and apply the v2 versions.

Yours,
Linus Walleij

Re: [PATCH 1/4] gpio: remove broken irq_to_gpio() interface

[Linus Walleij]

On Tue, Feb 16, 2016 at 4:45 PM, Arnd Bergmann <arnd@arndb.de> wrote:

> I've just sent v2 of the series, with a separate patch for MIPS
> that now conflicts with this one. Can you pick up the new patch
> instead?

OK I'll back out and apply the v2 versions.

Yours,
Linus Walleij

[PATCH v2 0/5] gpio: clean up irq_to_gpio and ARCH_NR_GPIOS

[Arnd Bergmann]

I noticed that arch/arm/include/asm/gpio.h can almost be removed,
after we have already removed the file for most other architectures
now.

When I removed it, I ran into problems with irq_to_gpio(), which
we had already killed off in ARM, but it survived (barely) in the
global headers and accidentally gained an invalid user

This kills it off some more.

The first patch should go as a bugfix into the MIPS tree, the
other ones should only get merged later, but I think that's fine
if they get submitted for 4.6. I left them as a series of five
patches to clarify the build-time dependency. Merging patch
2 before 1 turns the MIPS runtime error into a compiletime
error.

changes in v2:

* the MIPS change should now correctly fix the bug, thanks
  to Lars-Peter.

* I left out the ARM specific change for now, and just adapted
  the generic file so we don't need that any more.

*  Fixed the bug that Russell pointed out

	Arnd