Messages in this thread Patch in this message | | | From | Javier Martinez Canillas <> | Subject | [PATCH] driver core: add a debugfs entry to show deferred devices | Date | Tue, 19 Jun 2018 22:59:14 +0200 |
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For debugging purposes it may be useful to know what are the devices whose probe function was deferred. Add a debugfs entry showing that information.
$ cat /sys/kernel/debug/deferred_devices 48070000.i2c:twl@48:bci musb-hdrc.0.auto omapdrm.0
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
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Changes since RFC v1: - Remove unneeded ret variable from deferred_devs_show()
Changes since RFC v2: - Use DEFINE_SHOW_ATTRIBUTE() macro. - Don't propagate debugfs_create_file() error. - Remove IS_ENABLED(CONFIG_DEBUG_FS) guards. - Drop RFC prefix.
drivers/base/dd.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 1435d7281c6..8ec9e3cfbe4 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -16,6 +16,7 @@ * Copyright (c) 2007-2009 Novell Inc. */ +#include <linux/debugfs.h> #include <linux/device.h> #include <linux/delay.h> #include <linux/dma-mapping.h> @@ -224,6 +225,24 @@ void device_unblock_probing(void) driver_deferred_probe_trigger(); } +/* + * deferred_devs_show() - Show the devices in the deferred probe pending list. + */ +static int deferred_devs_show(struct seq_file *s, void *data) +{ + struct device_private *curr; + + mutex_lock(&deferred_probe_mutex); + + list_for_each_entry(curr, &deferred_probe_pending_list, deferred_probe) + seq_printf(s, "%s\n", dev_name(curr->device)); + + mutex_unlock(&deferred_probe_mutex); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(deferred_devs); + /** * deferred_probe_initcall() - Enable probing of deferred devices * @@ -233,6 +252,9 @@ void device_unblock_probing(void) */ static int deferred_probe_initcall(void) { + debugfs_create_file("deferred_devices", 0444, NULL, NULL, + &deferred_devs_fops); + driver_deferred_probe_enable = true; driver_deferred_probe_trigger(); /* Sort as many dependencies as possible before exiting initcalls */ -- 2.17.1
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