From: Dmitry Torokhov Date: Thu, 29 Sep 2016 15:13:14 +0000 (+0200) Subject: driver-core: add test module for asynchronous probing X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=79543cf2b18ea4a35f8864849d7ad8882ea8a23d;p=linux-beck.git driver-core: add test module for asynchronous probing This test module tries to test asynchronous driver probing by having a driver that sleeps for an extended period of time (5 secs) in its probe() method. It measures the time needed to register this driver (with device already registered) and a new device (with driver already registered). The module will fail to load if the time spent in register call is more than half the probing sleep time. As a sanity check the driver will then try to synchronously register driver and device and fail if registration takes less than half of the probing sleep time. Signed-off-by: Dmitry Torokhov Reviewed-by: Olof Johansson Signed-off-by: Guenter Roeck Signed-off-by: Thierry Escande Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index d02e7c0f5bfd..8defa9d87a6f 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -224,6 +224,8 @@ config DEBUG_TEST_DRIVER_REMOVE unusable. You should say N here unless you are explicitly looking to test this functionality. +source "drivers/base/test/Kconfig" + config SYS_HYPERVISOR bool default n diff --git a/drivers/base/Makefile b/drivers/base/Makefile index 2609ba20b396..f2816f6ff76a 100644 --- a/drivers/base/Makefile +++ b/drivers/base/Makefile @@ -24,5 +24,7 @@ obj-$(CONFIG_PINCTRL) += pinctrl.o obj-$(CONFIG_DEV_COREDUMP) += devcoredump.o obj-$(CONFIG_GENERIC_MSI_IRQ_DOMAIN) += platform-msi.o +obj-y += test/ + ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG diff --git a/drivers/base/test/Kconfig b/drivers/base/test/Kconfig new file mode 100644 index 000000000000..9aa0d45a60db --- /dev/null +++ b/drivers/base/test/Kconfig @@ -0,0 +1,9 @@ +config TEST_ASYNC_DRIVER_PROBE + tristate "Build kernel module to test asynchronous driver probing" + depends on m + help + Enabling this option produces a kernel module that allows + testing asynchronous driver probing by the device core. + The module name will be test_async_driver_probe.ko + + If unsure say N. diff --git a/drivers/base/test/Makefile b/drivers/base/test/Makefile new file mode 100644 index 000000000000..90477c5fd9f9 --- /dev/null +++ b/drivers/base/test/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_TEST_ASYNC_DRIVER_PROBE) += test_async_driver_probe.o diff --git a/drivers/base/test/test_async_driver_probe.c b/drivers/base/test/test_async_driver_probe.c new file mode 100644 index 000000000000..3a71e83e5d98 --- /dev/null +++ b/drivers/base/test/test_async_driver_probe.c @@ -0,0 +1,171 @@ +/* + * Copyright (C) 2014 Google, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include + +#define TEST_PROBE_DELAY (5 * 1000) /* 5 sec */ +#define TEST_PROBE_THRESHOLD (TEST_PROBE_DELAY / 2) + +static int test_probe(struct platform_device *pdev) +{ + dev_info(&pdev->dev, "sleeping for %d msecs in probe\n", + TEST_PROBE_DELAY); + msleep(TEST_PROBE_DELAY); + dev_info(&pdev->dev, "done sleeping\n"); + + return 0; +} + +static struct platform_driver async_driver = { + .driver = { + .name = "test_async_driver", + .owner = THIS_MODULE, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, + .probe = test_probe, +}; + +static struct platform_driver sync_driver = { + .driver = { + .name = "test_sync_driver", + .owner = THIS_MODULE, + .probe_type = PROBE_FORCE_SYNCHRONOUS, + }, + .probe = test_probe, +}; + +static struct platform_device *async_dev_1, *async_dev_2; +static struct platform_device *sync_dev_1; + +static int __init test_async_probe_init(void) +{ + ktime_t calltime, delta; + unsigned long long duration; + int error; + + pr_info("registering first asynchronous device...\n"); + + async_dev_1 = platform_device_register_simple("test_async_driver", 1, + NULL, 0); + if (IS_ERR(async_dev_1)) { + error = PTR_ERR(async_dev_1); + pr_err("failed to create async_dev_1: %d", error); + return error; + } + + pr_info("registering asynchronous driver...\n"); + calltime = ktime_get(); + error = platform_driver_register(&async_driver); + if (error) { + pr_err("Failed to register async_driver: %d\n", error); + goto err_unregister_async_dev_1; + } + + delta = ktime_sub(ktime_get(), calltime); + duration = (unsigned long long) ktime_to_ms(delta); + pr_info("registration took %lld msecs\n", duration); + if (duration > TEST_PROBE_THRESHOLD) { + pr_err("test failed: probe took too long\n"); + error = -ETIMEDOUT; + goto err_unregister_async_driver; + } + + pr_info("registering second asynchronous device...\n"); + calltime = ktime_get(); + async_dev_2 = platform_device_register_simple("test_async_driver", 2, + NULL, 0); + if (IS_ERR(async_dev_2)) { + error = PTR_ERR(async_dev_2); + pr_err("failed to create async_dev_2: %d", error); + goto err_unregister_async_driver; + } + + delta = ktime_sub(ktime_get(), calltime); + duration = (unsigned long long) ktime_to_ms(delta); + pr_info("registration took %lld msecs\n", duration); + if (duration > TEST_PROBE_THRESHOLD) { + pr_err("test failed: probe took too long\n"); + error = -ETIMEDOUT; + goto err_unregister_async_dev_2; + } + + pr_info("registering synchronous driver...\n"); + + error = platform_driver_register(&sync_driver); + if (error) { + pr_err("Failed to register async_driver: %d\n", error); + goto err_unregister_async_dev_2; + } + + pr_info("registering synchronous device...\n"); + calltime = ktime_get(); + sync_dev_1 = platform_device_register_simple("test_sync_driver", 1, + NULL, 0); + if (IS_ERR(async_dev_1)) { + error = PTR_ERR(sync_dev_1); + pr_err("failed to create sync_dev_1: %d", error); + goto err_unregister_sync_driver; + } + + delta = ktime_sub(ktime_get(), calltime); + duration = (unsigned long long) ktime_to_ms(delta); + pr_info("registration took %lld msecs\n", duration); + if (duration < TEST_PROBE_THRESHOLD) { + pr_err("test failed: probe was too quick\n"); + error = -ETIMEDOUT; + goto err_unregister_sync_dev_1; + } + + pr_info("completed successfully"); + + return 0; + +err_unregister_sync_dev_1: + platform_device_unregister(sync_dev_1); + +err_unregister_sync_driver: + platform_driver_unregister(&sync_driver); + +err_unregister_async_dev_2: + platform_device_unregister(async_dev_2); + +err_unregister_async_driver: + platform_driver_unregister(&async_driver); + +err_unregister_async_dev_1: + platform_device_unregister(async_dev_1); + + return error; +} +module_init(test_async_probe_init); + +static void __exit test_async_probe_exit(void) +{ + platform_driver_unregister(&async_driver); + platform_driver_unregister(&sync_driver); + platform_device_unregister(async_dev_1); + platform_device_unregister(async_dev_2); + platform_device_unregister(sync_dev_1); +} +module_exit(test_async_probe_exit); + +MODULE_DESCRIPTION("Test module for asynchronous driver probing"); +MODULE_AUTHOR("Dmitry Torokhov "); +MODULE_LICENSE("GPL");