The software node fw_devlink support already has its own kunit suite, but that verifies the fwnode links in isolation. Add GPIO tests that prove the ordering works in a real-life use-case: a GPIO consumer that references its provider via a software node.
The first suite registers the provider's software node, adds the consumer device first and checks that fw_devlink defers its probe until the provider has been added and bound. The second covers the fallback: with the provider's software node not yet registered no supplier link is created, so the consumer probes, devm_gpiod_get() returns -EPROBE_DEFER and the consumer only binds once the provider shows up. While at it: the existing gpio_unbind_with_consumers() test keeps the consumer bound while the provider goes away and then operates the orphaned descriptor. With software nodes now being covered by fw_devlink that would instead force-unbind the consumer along with the provider, so opt it out by setting FWNODE_FLAG_LINKS_ADDED. Signed-off-by: Bartosz Golaszewski <[email protected]> --- drivers/gpio/gpiolib-kunit.c | 272 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 265 insertions(+), 7 deletions(-) diff --git a/drivers/gpio/gpiolib-kunit.c b/drivers/gpio/gpiolib-kunit.c index 380b68f879e55433668353bb88067d561142a5bc..3def39f11ece46557cbdf8bae8642b2ad21232f0 100644 --- a/drivers/gpio/gpiolib-kunit.c +++ b/drivers/gpio/gpiolib-kunit.c @@ -12,11 +12,14 @@ #include <linux/platform_device.h> #include <linux/property.h> +#include <kunit/fwnode.h> #include <kunit/platform_device.h> #include <kunit/test.h> #define GPIO_TEST_PROVIDER "gpio-test-provider" #define GPIO_SWNODE_TEST_CONSUMER "gpio-swnode-test-consumer" +#define GPIO_PROBE_ORDER_TEST_CONSUMER "gpio-probe-order-test-consumer" +#define GPIO_PROBE_DEFER_TEST_CONSUMER "gpio-probe-defer-test-consumer" #define GPIO_UNBIND_TEST_CONSUMER "gpio-unbind-test-consumer" static int gpio_test_provider_get_direction(struct gpio_chip *gc, unsigned int offset) @@ -213,6 +216,251 @@ static struct kunit_suite gpio_swnode_lookup_test_suite = { .test_cases = gpio_swnode_lookup_tests, }; +static void gpio_swnode_unregister_swnode(void *data) +{ + software_node_unregister(data); +} + +struct gpio_probe_order_pdata { + int probe_count; + bool gpio_ok; +}; + +static const struct gpio_probe_order_pdata gpio_probe_order_pdata_template = { + .probe_count = 0, + .gpio_ok = false, +}; + +static int gpio_probe_order_consumer_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct gpio_probe_order_pdata *pdata = dev_get_platdata(dev); + struct gpio_desc *desc; + + pdata->probe_count++; + + desc = devm_gpiod_get(dev, "foo", GPIOD_OUT_HIGH); + if (IS_ERR(desc)) + return PTR_ERR(desc); + + pdata->gpio_ok = true; + + return 0; +} + +static struct platform_driver gpio_probe_order_consumer_driver = { + .probe = gpio_probe_order_consumer_probe, + .driver = { + .name = GPIO_PROBE_ORDER_TEST_CONSUMER, + }, +}; + +/* + * Verify that fw_devlink orders the probe of a GPIO consumer after its + * provider. The consumer references the provider through a software node and + * is registered first. fw_devlink must defer it before its driver's probe() + * is ever entered, so the consumer probes exactly once - only after the + * provider is added and bound. + */ +static void gpio_swnode_probe_order(struct kunit *test) +{ + struct gpio_probe_order_pdata *pdata; + struct platform_device_info pdevinfo; + struct property_entry properties[2]; + struct platform_device *prvd, *cons; + bool bound = false; + int ret; + + ret = kunit_platform_driver_register(test, &gpio_test_provider_driver); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = kunit_platform_driver_register(test, &gpio_probe_order_consumer_driver); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = software_node_register(&gpio_test_provider_swnode); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = kunit_add_action_or_reset(test, gpio_swnode_unregister_swnode, + (void *)&gpio_test_provider_swnode); + KUNIT_ASSERT_EQ(test, ret, 0); + + properties[0] = PROPERTY_ENTRY_GPIO("foo-gpios", + &gpio_test_provider_swnode, + 0, GPIO_ACTIVE_HIGH); + properties[1] = (struct property_entry){ }; + + pdevinfo = (struct platform_device_info){ + .name = GPIO_PROBE_ORDER_TEST_CONSUMER, + .id = PLATFORM_DEVID_NONE, + .data = &gpio_probe_order_pdata_template, + .size_data = sizeof(gpio_probe_order_pdata_template), + .properties = properties, + }; + + cons = kunit_platform_device_register_full(test, &pdevinfo); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cons); + + wait_for_device_probe(); + scoped_guard(device, &cons->dev) + bound = device_is_bound(&cons->dev); + + KUNIT_ASSERT_FALSE(test, bound); + + pdata = dev_get_platdata(&cons->dev); + KUNIT_ASSERT_EQ(test, pdata->probe_count, 0); + KUNIT_ASSERT_FALSE(test, pdata->gpio_ok); + + pdevinfo = (struct platform_device_info){ + .name = GPIO_TEST_PROVIDER, + .id = PLATFORM_DEVID_NONE, + .swnode = &gpio_test_provider_swnode, + }; + + prvd = kunit_platform_device_register_full(test, &pdevinfo); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, prvd); + + wait_for_device_probe(); + + scoped_guard(device, &prvd->dev) + bound = device_is_bound(&prvd->dev); + KUNIT_ASSERT_TRUE(test, bound); + + scoped_guard(device, &cons->dev) + bound = device_is_bound(&cons->dev); + KUNIT_ASSERT_TRUE(test, bound); + + pdata = dev_get_platdata(&cons->dev); + KUNIT_ASSERT_EQ(test, pdata->probe_count, 1); + KUNIT_ASSERT_TRUE(test, pdata->gpio_ok); +} + +struct gpio_probe_defer_pdata { + int probe_count; + int gpio_err; +}; + +static const struct gpio_probe_defer_pdata gpio_probe_defer_pdata_template = { + .probe_count = 0, + .gpio_err = 0, +}; + +static int gpio_probe_defer_consumer_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct gpio_probe_defer_pdata *pdata = dev_get_platdata(dev); + struct gpio_desc *desc; + + pdata->probe_count++; + + desc = devm_gpiod_get(dev, "foo", GPIOD_OUT_HIGH); + if (IS_ERR(desc)) { + pdata->gpio_err = PTR_ERR(desc); + return pdata->gpio_err; + } + + pdata->gpio_err = 0; + + return 0; +} + +static struct platform_driver gpio_probe_defer_consumer_driver = { + .probe = gpio_probe_defer_consumer_probe, + .driver = { + .name = GPIO_PROBE_DEFER_TEST_CONSUMER, + }, +}; + +/* + * Verify that a GPIO consumer referencing a provider whose software node is + * not registered yet, defers its probe instead of failing. + * + * The provider software node is deliberately left unregistered when the + * consumer is added. fw_devlink cannot resolve the reference, so it creates no + * supplier link and does not order the consumer - the consumer's probe() runs + * and reaches devm_gpiod_get(). The swnode GPIO lookup returns -ENOTCONN for a + * reference to an unregistered node, which gpiolib maps to -EPROBE_DEFER. Once + * the provider software node and device appear, the deferred consumer probes + * again and binds. + */ +static void gpio_swnode_probe_defer_on_unregistered(struct kunit *test) +{ + struct gpio_probe_defer_pdata *pdata; + struct platform_device_info pdevinfo; + struct property_entry properties[2]; + struct platform_device *prvd, *cons; + struct fwnode_handle *fwnode; + bool bound = false; + int ret; + + ret = kunit_platform_driver_register(test, &gpio_test_provider_driver); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = kunit_platform_driver_register(test, &gpio_probe_defer_consumer_driver); + KUNIT_ASSERT_EQ(test, ret, 0); + + properties[0] = PROPERTY_ENTRY_GPIO("foo-gpios", + &gpio_test_provider_swnode, + 0, GPIO_ACTIVE_HIGH); + properties[1] = (struct property_entry){ }; + + pdevinfo = (struct platform_device_info){ + .name = GPIO_PROBE_DEFER_TEST_CONSUMER, + .id = PLATFORM_DEVID_NONE, + .data = &gpio_probe_defer_pdata_template, + .size_data = sizeof(gpio_probe_defer_pdata_template), + .properties = properties, + }; + + cons = kunit_platform_device_register_full(test, &pdevinfo); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cons); + + wait_for_device_probe(); + scoped_guard(device, &cons->dev) + bound = device_is_bound(&cons->dev); + + KUNIT_ASSERT_FALSE(test, bound); + + pdata = dev_get_platdata(&cons->dev); + KUNIT_ASSERT_GT(test, pdata->probe_count, 0); + KUNIT_ASSERT_EQ(test, pdata->gpio_err, -EPROBE_DEFER); + + fwnode = kunit_software_node_register(test, &gpio_test_provider_swnode); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fwnode); + + pdevinfo = (struct platform_device_info){ + .name = GPIO_TEST_PROVIDER, + .id = PLATFORM_DEVID_NONE, + .swnode = &gpio_test_provider_swnode, + }; + + prvd = kunit_platform_device_register_full(test, &pdevinfo); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, prvd); + + wait_for_device_probe(); + + scoped_guard(device, &prvd->dev) + bound = device_is_bound(&prvd->dev); + KUNIT_ASSERT_TRUE(test, bound); + + scoped_guard(device, &cons->dev) + bound = device_is_bound(&cons->dev); + KUNIT_ASSERT_TRUE(test, bound); + + pdata = dev_get_platdata(&cons->dev); + KUNIT_ASSERT_EQ(test, pdata->gpio_err, 0); +} + +static struct kunit_case gpio_swnode_probe_order_tests[] = { + KUNIT_CASE(gpio_swnode_probe_order), + KUNIT_CASE(gpio_swnode_probe_defer_on_unregistered), + { } +}; + +static struct kunit_suite gpio_swnode_probe_order_test_suite = { + .name = "gpio-swnode-probe-order", + .test_cases = gpio_swnode_probe_order_tests, +}; + static BLOCKING_NOTIFIER_HEAD(gpio_unbind_notifier); struct gpio_unbind_consumer_drvdata { @@ -310,15 +558,24 @@ static void gpio_unbind_with_consumers(struct kunit *test) 0, GPIO_ACTIVE_HIGH); properties[1] = (struct property_entry){ }; - pdevinfo = (struct platform_device_info){ - .name = GPIO_UNBIND_TEST_CONSUMER, - .id = PLATFORM_DEVID_NONE, - .properties = properties, - }; - - cons = kunit_platform_device_register_full(test, &pdevinfo); + /* + * This test deliberately keeps the consumer bound while the provider + * is unregistered. fw_devlink would force-unbind the consumer before + * the provider so use the FWNODE_FLAG_LINKS_ADDED flag to opt out of + * it as a workaround. + */ + cons = kunit_platform_device_alloc(test, GPIO_UNBIND_TEST_CONSUMER, + PLATFORM_DEVID_NONE); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cons); + ret = device_create_managed_software_node(&cons->dev, properties, NULL); + KUNIT_ASSERT_EQ(test, ret, 0); + + fwnode_set_flag(dev_fwnode(&cons->dev), FWNODE_FLAG_LINKS_ADDED); + + ret = kunit_platform_device_add(test, cons); + KUNIT_ASSERT_EQ(test, ret, 0); + wait_for_device_probe(); scoped_guard(device, &cons->dev) bound = device_is_bound(&cons->dev); @@ -350,6 +607,7 @@ static struct kunit_suite gpio_unbind_with_consumers_test_suite = { kunit_test_suites( &gpio_swnode_lookup_test_suite, + &gpio_swnode_probe_order_test_suite, &gpio_unbind_with_consumers_test_suite, ); -- 2.47.3
