[PATCH 3/4] log: Add a way to enable/disable a log device

[Heinrich Schuchardt]

Am 12. September 2020 20:28:49 MESZ schrieb Simon Glass <sjg at chromium.org>:
>At present all log devices are enabled by default. Add a function to
>allow
>devices to be disabled or enabled at runtime.

Should this capability be added to the log command?

Regards

Heinrich

>
>Signed-off-by: Simon Glass <sjg at chromium.org>
>---
>
> common/log.c              | 38 ++++++++++++++++++++++++++++++++++++++
> include/log.h             | 17 +++++++++++++++++
> test/log/log_test.c       |  7 +++++++
> test/py/tests/test_log.py |  8 ++++++++
> 4 files changed, 70 insertions(+)
>
>diff --git a/common/log.c b/common/log.c
>index ce528fe4535..a9aacfaf354 100644
>--- a/common/log.c
>+++ b/common/log.c
>@@ -297,6 +297,44 @@ int log_remove_filter(const char *drv_name, int
>filter_num)
> 	return -ENOENT;
> }
> 
>+/**
>+ * log_find_device_by_drv() - Find a device by its driver
>+ *
>+ * @drv: Log driver
>+ * @return Device associated with that driver, or NULL if not found
>+ */
>+static struct log_device *log_find_device_by_drv(struct log_driver
>*drv)
>+{
>+	struct log_device *ldev;
>+
>+	list_for_each_entry(ldev, &gd->log_head, sibling_node) {
>+		if (ldev->drv == drv)
>+			return ldev;
>+	}
>+	/*
>+	 * It is quite hard to pass an invalid driver since passing an
>unknown
>+	 * LOG_GET_DRIVER(xxx) would normally produce a compilation error.
>But
>+	 * it is possible to pass NULL, for example, so this
>+	 */
>+
>+	return NULL;
>+}
>+
>+int log_device_set_enable(struct log_driver *drv, bool enable)
>+{
>+	struct log_device *ldev;
>+
>+	ldev = log_find_device_by_drv(drv);
>+	if (!ldev)
>+		return -ENOENT;
>+	if (enable)
>+		ldev->flags |= LOGDF_ENABLE;
>+	else
>+		ldev->flags &= ~LOGDF_ENABLE;
>+
>+	return 0;
>+}
>+
> int log_init(void)
> {
>	struct log_driver *drv = ll_entry_start(struct log_driver,
>log_driver);
>diff --git a/include/log.h b/include/log.h
>index d28bc1ef0e4..4acc087b2e9 100644
>--- a/include/log.h
>+++ b/include/log.h
>@@ -388,6 +388,10 @@ struct log_filter {
> #define LOG_DRIVER(_name) \
> 	ll_entry_declare(struct log_driver, _name, log_driver)
> 
>+/* Get a pointer to a given driver */
>+#define LOG_GET_DRIVER(__name)						\
>+	ll_entry_get(struct log_driver, __name, log_driver)
>+
> /**
>  * log_get_cat_name() - Get the name of a category
>  *
>@@ -465,6 +469,19 @@ int log_add_filter(const char *drv_name, enum
>log_category_t cat_list[],
>  */
> int log_remove_filter(const char *drv_name, int filter_num);
> 
>+/**
>+ * log_device_set_enable() - Enable or disable a log device
>+ *
>+ * Devices are referenced by their driver, so use LOG_GET_DRIVER(name)
>to pass
>+ * the driver to this function. For example if the driver is declared
>with
>+ * LOG_DRIVER(wibble) then pass LOG_GET_DRIVER(wibble) here.
>+ *
>+ * @drv: Driver of device to enable
>+ * @enable: true to enable, false to disable
>+ * @return 0 if OK, -ENOENT if the driver was not found
>+ */
>+int log_device_set_enable(struct log_driver *drv, bool enable);
>+
> #if CONFIG_IS_ENABLED(LOG)
> /**
>  * log_init() - Set up the log system ready for use
>diff --git a/test/log/log_test.c b/test/log/log_test.c
>index fdee5e6757f..6a60ff6be3c 100644
>--- a/test/log/log_test.c
>+++ b/test/log/log_test.c
>@@ -196,6 +196,13 @@ static int log_test(int testnum)
> 		log_io("level %d\n", LOGL_DEBUG_IO);
> 		break;
> 	}
>+	case 11:
>+		log_err("default\n");
>+		ret = log_device_set_enable(LOG_GET_DRIVER(console), false);
>+		log_err("disabled\n");
>+		ret = log_device_set_enable(LOG_GET_DRIVER(console), true);
>+		log_err("enabled\n");
>+		break;
> 	}
> 
> 	return 0;
>diff --git a/test/py/tests/test_log.py b/test/py/tests/test_log.py
>index ddc28f19ee8..275f9382d2f 100644
>--- a/test/py/tests/test_log.py
>+++ b/test/py/tests/test_log.py
>@@ -92,6 +92,13 @@ def test_log(u_boot_console):
>         for i in range(7):
>             assert 'log_test() level %d' % i == next(lines)
> 
>+    def test11():
>+        """Test use of log_device_set_enable()"""
>+        lines = run_test(11)
>+        assert 'log_test() default'
>+        # disabled should not be displayed
>+        assert 'log_test() enabled'
>+
>  # TODO(sjg at chromium.org): Consider structuring this as separate tests
>     cons = u_boot_console
>     test0()
>@@ -105,6 +112,7 @@ def test_log(u_boot_console):
>     test8()
>     test9()
>     test10()
>+    test11()
> 
> @pytest.mark.buildconfigspec('cmd_log')
> def test_log_format(u_boot_console):