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 <javi...@redhat.com>
---
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
