[PATCH] gpiolib: acpi: Fix failed in acpi_gpiochip_find() by adding parent node match

[PATCH] gpiolib: acpi: Fix failed in acpi_gpiochip_find() by adding parent node match

[Devyn Liu]

Previous patch modified the standard used by acpi_gpiochip_find()
to match device nodes. Using the device node set in gc->gpiodev->d-
ev instead of gc->parent.

However, there is a situation in gpio-dwapb where the GPIO device
driver will set gc->fwnode for each port corresponding to a child
node under a GPIO device, so gc->gpiodev->dev will be assigned the
value of each child node in gpiochip_add_data().

gpio-dwapb.c:
128,31 static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
			       struct dwapb_port_property *pp,
			       unsigned int offs);
port->gc.fwnode = pp->fwnode;

693,39 static int dwapb_gpio_probe;
err = dwapb_gpio_add_port(gpio, &pdata->properties[i], i);

When other drivers request GPIO pin resources through the GPIO device
node provided by ACPI (corresponding to the parent node), the change
of the matching object to gc->gpiodev->dev in acpi_gpiochip_find()
only allows finding the value of each port (child node), resulting
in a failed request.

Reapply the condition of using gc->parent for match in acpi_gpio-
chip_find() in the code can compatible with the problem of gpio-dwapb,
and will not affect the two cases mentioned in the patch:
1. There is no setting for gc->fwnode.
2. The case that depends on using gc->fwnode for match.

Fixes: 5062e4c14b75 ("gpiolib: acpi: use the fwnode in acpi_gpiochip_find()")
Fixes: 067dbc1ea5ce ("gpiolib: acpi: Don't use GPIO chip fwnode in acpi_gpiochip_find()")
Signed-off-by: Devyn Liu <liudingyuan@huawei.com>
---
 drivers/gpio/gpiolib-acpi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 7f140df40f35..6078fea3e021 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -128,7 +128,8 @@ static bool acpi_gpio_deferred_req_irqs_done;
 
 static int acpi_gpiochip_find(struct gpio_chip *gc, const void *data)
 {
-	return device_match_acpi_handle(&gc->gpiodev->dev, data);
+	return device_match_acpi_handle(&gc->gpiodev->dev, data) ||
+		(gc->parent && device_match_acpi_handle(gc->parent, data));
 }
 
 /**
-- 
2.30.0

Re: [PATCH] gpiolib: acpi: Fix failed in acpi_gpiochip_find() by adding parent node match

[Andy Shevchenko]

On Mon, May 13, 2024 at 03:59:01PM +0800, Devyn Liu wrote:
> Previous patch modified the standard used by acpi_gpiochip_find()
> to match device nodes. Using the device node set in gc->gpiodev->d-
> ev instead of gc->parent.
> 
> However, there is a situation in gpio-dwapb where the GPIO device
> driver will set gc->fwnode for each port corresponding to a child
> node under a GPIO device, so gc->gpiodev->dev will be assigned the
> value of each child node in gpiochip_add_data().
> 
> gpio-dwapb.c:
> 128,31 static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
> 			       struct dwapb_port_property *pp,
> 			       unsigned int offs);
> port->gc.fwnode = pp->fwnode;
> 
> 693,39 static int dwapb_gpio_probe;
> err = dwapb_gpio_add_port(gpio, &pdata->properties[i], i);
> 
> When other drivers request GPIO pin resources through the GPIO device
> node provided by ACPI (corresponding to the parent node), the change
> of the matching object to gc->gpiodev->dev in acpi_gpiochip_find()
> only allows finding the value of each port (child node), resulting
> in a failed request.
> 
> Reapply the condition of using gc->parent for match in acpi_gpio-
> chip_find() in the code can compatible with the problem of gpio-dwapb,
> and will not affect the two cases mentioned in the patch:
> 1. There is no setting for gc->fwnode.
> 2. The case that depends on using gc->fwnode for match.

Thanks for the report, analysis, and patch.

...

>  static int acpi_gpiochip_find(struct gpio_chip *gc, const void *data)
>  {
> -	return device_match_acpi_handle(&gc->gpiodev->dev, data);
> +	return device_match_acpi_handle(&gc->gpiodev->dev, data) ||
> +		(gc->parent && device_match_acpi_handle(gc->parent, data));
>  }

I'm wondering if the below approach will work for all:

static int acpi_gpiochip_find(struct gpio_chip *gc, const void *data)
{
	struct device *dev = acpi_get_first_physical_node(ACPI_COMPANION(&gc->gpiodev->dev));

	return device_match_acpi_handle(dev, data);
}

Cc'ing to Benjamin for testing and commenting.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH] gpiolib: acpi: Fix failed in acpi_gpiochip_find() by adding parent node match

[Benjamin Tissoires]

On May 13 2024, Andy Shevchenko wrote:
> On Mon, May 13, 2024 at 03:59:01PM +0800, Devyn Liu wrote:
> > Previous patch modified the standard used by acpi_gpiochip_find()
> > to match device nodes. Using the device node set in gc->gpiodev->d-
> > ev instead of gc->parent.
> > 
> > However, there is a situation in gpio-dwapb where the GPIO device
> > driver will set gc->fwnode for each port corresponding to a child
> > node under a GPIO device, so gc->gpiodev->dev will be assigned the
> > value of each child node in gpiochip_add_data().
> > 
> > gpio-dwapb.c:
> > 128,31 static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
> > 			       struct dwapb_port_property *pp,
> > 			       unsigned int offs);
> > port->gc.fwnode = pp->fwnode;
> > 
> > 693,39 static int dwapb_gpio_probe;
> > err = dwapb_gpio_add_port(gpio, &pdata->properties[i], i);
> > 
> > When other drivers request GPIO pin resources through the GPIO device
> > node provided by ACPI (corresponding to the parent node), the change
> > of the matching object to gc->gpiodev->dev in acpi_gpiochip_find()
> > only allows finding the value of each port (child node), resulting
> > in a failed request.
> > 
> > Reapply the condition of using gc->parent for match in acpi_gpio-
> > chip_find() in the code can compatible with the problem of gpio-dwapb,
> > and will not affect the two cases mentioned in the patch:
> > 1. There is no setting for gc->fwnode.
> > 2. The case that depends on using gc->fwnode for match.
> 
> Thanks for the report, analysis, and patch.
> 
> ...
> 
> >  static int acpi_gpiochip_find(struct gpio_chip *gc, const void *data)
> >  {
> > -	return device_match_acpi_handle(&gc->gpiodev->dev, data);
> > +	return device_match_acpi_handle(&gc->gpiodev->dev, data) ||
> > +		(gc->parent && device_match_acpi_handle(gc->parent, data));
> >  }

The original patch (from Devyn) is:
Tested-by: Benjamin Tissoires <bentiss@kernel.org>

For reference, a successful run can be seen at:
https://gitlab.freedesktop.org/bentiss/hid/-/jobs/58661693

> 
> I'm wondering if the below approach will work for all:
> 
> static int acpi_gpiochip_find(struct gpio_chip *gc, const void *data)
> {
> 	struct device *dev = acpi_get_first_physical_node(ACPI_COMPANION(&gc->gpiodev->dev));
> 
> 	return device_match_acpi_handle(dev, data);
> }

Looks like I get a bad dev pointer in this situation:
https://gitlab.freedesktop.org/bentiss/hid/-/jobs/58662689#L704

Not sure if this is because the not-yet-upstream patches I have in
hid-cp2112 are doing something wrong or if there is a good reason for
it...

The patch that adds fwnode to hid-cp2112 are:
https://gitlab.freedesktop.org/bentiss/gitlab-kernel-ci/-/blob/master/VM/0002-HID-usbhid-Share-USB-device-firmware-node-with-child.patch
https://gitlab.freedesktop.org/bentiss/gitlab-kernel-ci/-/blob/master/VM/0003-HID-cp2112-Fwnode-Support.patch

both of those patches are applied before compilation in the CI run from
above.

> 
> Cc'ing to Benjamin for testing and commenting.

TL;DR: initial patch is fine, yours will probably need a check on the
dev return value, so not sure if we gain a lot...

Cheers,
Benjamin

Re: [PATCH] gpiolib: acpi: Fix failed in acpi_gpiochip_find() by adding parent node match

[Mika Westerberg]

On Mon, May 13, 2024 at 03:59:01PM +0800, Devyn Liu wrote:
> Previous patch modified the standard used by acpi_gpiochip_find()
> to match device nodes. Using the device node set in gc->gpiodev->d-
> ev instead of gc->parent.
> 
> However, there is a situation in gpio-dwapb where the GPIO device
> driver will set gc->fwnode for each port corresponding to a child
> node under a GPIO device, so gc->gpiodev->dev will be assigned the
> value of each child node in gpiochip_add_data().
> 
> gpio-dwapb.c:
> 128,31 static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
> 			       struct dwapb_port_property *pp,
> 			       unsigned int offs);
> port->gc.fwnode = pp->fwnode;
> 
> 693,39 static int dwapb_gpio_probe;
> err = dwapb_gpio_add_port(gpio, &pdata->properties[i], i);
> 
> When other drivers request GPIO pin resources through the GPIO device
> node provided by ACPI (corresponding to the parent node), the change
> of the matching object to gc->gpiodev->dev in acpi_gpiochip_find()
> only allows finding the value of each port (child node), resulting
> in a failed request.
> 
> Reapply the condition of using gc->parent for match in acpi_gpio-
> chip_find() in the code can compatible with the problem of gpio-dwapb,
> and will not affect the two cases mentioned in the patch:
> 1. There is no setting for gc->fwnode.
> 2. The case that depends on using gc->fwnode for match.
> 
> Fixes: 5062e4c14b75 ("gpiolib: acpi: use the fwnode in acpi_gpiochip_find()")
> Fixes: 067dbc1ea5ce ("gpiolib: acpi: Don't use GPIO chip fwnode in acpi_gpiochip_find()")
> Signed-off-by: Devyn Liu <liudingyuan@huawei.com>

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Re: [PATCH] gpiolib: acpi: Fix failed in acpi_gpiochip_find() by adding parent node match

[Andy Shevchenko]

On Mon, May 20, 2024 at 07:37:49AM +0300, Mika Westerberg wrote:
> On Mon, May 13, 2024 at 03:59:01PM +0800, Devyn Liu wrote:
> > Previous patch modified the standard used by acpi_gpiochip_find()
> > to match device nodes. Using the device node set in gc->gpiodev->d-
> > ev instead of gc->parent.
> > 
> > However, there is a situation in gpio-dwapb where the GPIO device
> > driver will set gc->fwnode for each port corresponding to a child
> > node under a GPIO device, so gc->gpiodev->dev will be assigned the
> > value of each child node in gpiochip_add_data().
> > 
> > gpio-dwapb.c:
> > 128,31 static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
> > 			       struct dwapb_port_property *pp,
> > 			       unsigned int offs);
> > port->gc.fwnode = pp->fwnode;
> > 
> > 693,39 static int dwapb_gpio_probe;
> > err = dwapb_gpio_add_port(gpio, &pdata->properties[i], i);
> > 
> > When other drivers request GPIO pin resources through the GPIO device
> > node provided by ACPI (corresponding to the parent node), the change
> > of the matching object to gc->gpiodev->dev in acpi_gpiochip_find()
> > only allows finding the value of each port (child node), resulting
> > in a failed request.
> > 
> > Reapply the condition of using gc->parent for match in acpi_gpio-
> > chip_find() in the code can compatible with the problem of gpio-dwapb,
> > and will not affect the two cases mentioned in the patch:
> > 1. There is no setting for gc->fwnode.
> > 2. The case that depends on using gc->fwnode for match.
> > 
> > Fixes: 5062e4c14b75 ("gpiolib: acpi: use the fwnode in acpi_gpiochip_find()")
> > Fixes: 067dbc1ea5ce ("gpiolib: acpi: Don't use GPIO chip fwnode in acpi_gpiochip_find()")
> > Signed-off-by: Devyn Liu <liudingyuan@huawei.com>
> 
> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Pushed to my review and testing queue, thanks!

-- 
With Best Regards,
Andy Shevchenko