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authorDmitry Torokhov <dtor@chromium.org>2016-09-29 18:13:14 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-11-10 19:28:16 +0300
commit79543cf2b18ea4a35f8864849d7ad8882ea8a23d (patch)
tree1a13abe673b27f0eaa3267022a0a4a7805fee790 /drivers/base/test
parent6751667a29d6fd64afb9ce30567ad616b68ed789 (diff)
downloadlinux-79543cf2b18ea4a35f8864849d7ad8882ea8a23d.tar.xz
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 <dtor@chromium.org> Reviewed-by: Olof Johansson <olofj@chromium.org> Signed-off-by: Guenter Roeck <groeck@chromium.org> Signed-off-by: Thierry Escande <thierry.escande@collabora.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/test')
-rw-r--r--drivers/base/test/Kconfig9
-rw-r--r--drivers/base/test/Makefile1
-rw-r--r--drivers/base/test/test_async_driver_probe.c171
3 files changed, 181 insertions, 0 deletions
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 <linux/delay.h>
+#include <linux/init.h>
+#include <linux/hrtimer.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/time.h>
+
+#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 <dtor@chromium.org>");
+MODULE_LICENSE("GPL");