[PATCH 6.9 145/374] gpiolib: acpi: Fix failed in acpi_gpiochip_find() by adding parent node match

Greg Kroah-Hartman
2024-06-06T14:09:52Z

From: Devyn Liu <liudingyuan@huawei.com>

[ Upstream commit adbc49a5a8c6fcf7be154c2e30213bbf472940da ]

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>
Tested-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpio/gpiolib-acpi.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 7f140df40f35b..c1e190d3ea244 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -128,7 +128,24 @@ 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);
+ /* First check the actual GPIO device */
+ if (device_match_acpi_handle(&gc->gpiodev->dev, data))
+ return true;
+
+ /*
+ * When the ACPI device is artificially split to the banks of GPIOs,
+ * where each of them is represented by a separate GPIO device,
+ * the firmware node of the physical device may not be shared among
+ * the banks as they may require different values for the same property,
+ * e.g., number of GPIOs in a certain bank. In such case the ACPI handle
+ * of a GPIO device is NULL and can not be used. Hence we have to check
+ * the parent device to be sure that there is no match before bailing
+ * out.
+ */
+ if (gc->parent)
+ return device_match_acpi_handle(gc->parent, data);
+
+ return false;
}

/**
--
2.43.0