gpiolib: Show IRQ line in debugfs

[PATCH v2 2/2] gpiolib: Show more info for interrupt only lines in debugfs

Posted by Andy Shevchenko 1 year, 6 months ago

Show more info for interrupt only lines in debugfs. It's useful
to monitor the lines that have been never requested as GPIOs,
but IRQs.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/gpio/gpiolib.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index a6032b84ba98..f3b2f5c4781d 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4888,11 +4888,11 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
 
 	for_each_gpio_desc(gc, desc) {
 		guard(srcu)(&desc->gdev->desc_srcu);
-		if (test_bit(FLAG_REQUESTED, &desc->flags)) {
+		is_irq = test_bit(FLAG_USED_AS_IRQ, &desc->flags);
+		if (is_irq || test_bit(FLAG_REQUESTED, &desc->flags)) {
 			gpiod_get_direction(desc);
 			is_out = test_bit(FLAG_IS_OUT, &desc->flags);
 			value = gpio_chip_get_value(gc, desc);
-			is_irq = test_bit(FLAG_USED_AS_IRQ, &desc->flags);
 			active_low = test_bit(FLAG_ACTIVE_LOW, &desc->flags);
 			seq_printf(s, " gpio-%-3u (%-20.20s|%-20.20s) %s %s %s%s\n",
 				   gpio, desc->name ?: "", gpiod_get_label(desc),
-- 
2.43.0.rc1.1336.g36b5255a03ac

Re: [PATCH v2 2/2] gpiolib: Show more info for interrupt only lines in debugfs

Posted by Alexander Stein 1 year, 6 months ago

Hi,

Am Donnerstag, 30. Mai 2024, 21:12:30 CEST schrieb Andy Shevchenko:
> Show more info for interrupt only lines in debugfs. It's useful
> to monitor the lines that have been never requested as GPIOs,
> but IRQs.

I was trying to test this on TQMa8MPQL (i.MX8MP) using gpio-mxc.c.
But apparently this series only has an effect when gpiochip_lock_as_irq()
is called eventually. I'm wondering what needs to be done so IRQ only
GPIOs are listed in debugfs. Using irq_request_resources/irq_release_resources
similar to what pinctrl-at91.c is doing?

Best regards,
Alexander

> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  drivers/gpio/gpiolib.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index a6032b84ba98..f3b2f5c4781d 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -4888,11 +4888,11 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
>  
>  	for_each_gpio_desc(gc, desc) {
>  		guard(srcu)(&desc->gdev->desc_srcu);
> -		if (test_bit(FLAG_REQUESTED, &desc->flags)) {
> +		is_irq = test_bit(FLAG_USED_AS_IRQ, &desc->flags);
> +		if (is_irq || test_bit(FLAG_REQUESTED, &desc->flags)) {
>  			gpiod_get_direction(desc);
>  			is_out = test_bit(FLAG_IS_OUT, &desc->flags);
>  			value = gpio_chip_get_value(gc, desc);
> -			is_irq = test_bit(FLAG_USED_AS_IRQ, &desc->flags);
>  			active_low = test_bit(FLAG_ACTIVE_LOW, &desc->flags);
>  			seq_printf(s, " gpio-%-3u (%-20.20s|%-20.20s) %s %s %s%s\n",
>  				   gpio, desc->name ?: "", gpiod_get_label(desc),
> 


-- 
TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
Amtsgericht München, HRB 105018
Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
http://www.tq-group.com/

Re: [PATCH v2 2/2] gpiolib: Show more info for interrupt only lines in debugfs

Posted by Andy Shevchenko 1 year, 6 months ago

On Fri, May 31, 2024 at 01:19:56PM +0200, Alexander Stein wrote:
> Hi,
> 
> Am Donnerstag, 30. Mai 2024, 21:12:30 CEST schrieb Andy Shevchenko:
> > Show more info for interrupt only lines in debugfs. It's useful
> > to monitor the lines that have been never requested as GPIOs,
> > but IRQs.
> 
> I was trying to test this on TQMa8MPQL (i.MX8MP) using gpio-mxc.c.
> But apparently this series only has an effect when gpiochip_lock_as_irq()
> is called eventually. I'm wondering what needs to be done so IRQ only
> GPIOs are listed in debugfs. Using irq_request_resources/irq_release_resources
> similar to what pinctrl-at91.c is doing?

For the record on Intel Galileo Gen2 I see this difference

Before:

gpiochip4: GPIOs 8-15, parent: platform/gpio-dwapb.1, gpio-dwapb.1:
gpio-10  (                    |spi169 CS0          ) out hi

After:

gpiochip4: GPIOs 8-15, parent: platform/gpio-dwapb.1, gpio-dwapb.1:
gpio-9   (                    |irq                 ) in  hi IRQ ACTIVE LOW
gpio-10  (                    |spi169 CS0          ) out hi

but it's handled via gpiolib-acpi.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2 2/2] gpiolib: Show more info for interrupt only lines in debugfs

Posted by Andy Shevchenko 1 year, 6 months ago

On Fri, May 31, 2024 at 01:19:56PM +0200, Alexander Stein wrote:
> Am Donnerstag, 30. Mai 2024, 21:12:30 CEST schrieb Andy Shevchenko:
> > Show more info for interrupt only lines in debugfs. It's useful
> > to monitor the lines that have been never requested as GPIOs,
> > but IRQs.
> 
> I was trying to test this on TQMa8MPQL (i.MX8MP) using gpio-mxc.c.

Thank you for trying!

> But apparently this series only has an effect when gpiochip_lock_as_irq()
> is called eventually. I'm wondering what needs to be done so IRQ only
> GPIOs are listed in debugfs. Using irq_request_resources/irq_release_resources
> similar to what pinctrl-at91.c is doing?

I haven't looked deeply into this and I don't know if it's relevant, but...

The idea is that GPIO driver has an IRQ chip that announces handle_bad_irq()
as a handler and IRQ_TYPE_NONE as default type at probe stage. It also needs
to implement ->set_irq_type() callback where actual handler is going to be
locked.

That's what I do not see implemented in the driver. Moreover, I do see it
implements its own ->to_irq() callback which shouldn't be there.

Taking all above into consideration _I think_ the drivers need a bit of
refreshments.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2 2/2] gpiolib: Show more info for interrupt only lines in debugfs

Posted by Alexander Stein 1 year, 6 months ago

Hi,

Am Freitag, 31. Mai 2024, 15:30:58 CEST schrieb Andy Shevchenko:
> On Fri, May 31, 2024 at 01:19:56PM +0200, Alexander Stein wrote:
> > Am Donnerstag, 30. Mai 2024, 21:12:30 CEST schrieb Andy Shevchenko:
> > > Show more info for interrupt only lines in debugfs. It's useful
> > > to monitor the lines that have been never requested as GPIOs,
> > > but IRQs.
> > 
> > I was trying to test this on TQMa8MPQL (i.MX8MP) using gpio-mxc.c.
> 
> Thank you for trying!
> 
> > But apparently this series only has an effect when gpiochip_lock_as_irq()
> > is called eventually. I'm wondering what needs to be done so IRQ only
> > GPIOs are listed in debugfs. Using irq_request_resources/irq_release_resources
> > similar to what pinctrl-at91.c is doing?
> 
> I haven't looked deeply into this and I don't know if it's relevant, but...
> 
> The idea is that GPIO driver has an IRQ chip that announces handle_bad_irq()
> as a handler and IRQ_TYPE_NONE as default type at probe stage. It also needs
> to implement ->set_irq_type() callback where actual handler is going to be
> locked.
> 
> That's what I do not see implemented in the driver. Moreover, I do see it
> implements its own ->to_irq() callback which shouldn't be there.
> 
> Taking all above into consideration _I think_ the drivers need a bit of
> refreshments.

I noticed this driver is using irq_chip_generic and a dedicated irq domain.
I'm not sure if this is superseded meanwhile using the integrated IRQ chip
inside that GPIO chip.
Thanks for looking into this.

Best regards,
Alexander
-- 
TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
Amtsgericht München, HRB 105018
Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
http://www.tq-group.com/