From: Hans de Goede <hdegoede@redhat.com>
Date: Sat, 17 Aug 2019 20:43:38 +0200
Subject: usb: typec: tcpm: Use usb_debug_root as root for our debugfs entry
Git-commit: 9f4bc2ed74086e51cfc75754adfcbff86f28597a
Patch-mainline: v5.4-rc1
References: jsc#SLE-13918

Use usb_debug_root as root for our debugfs entry instead of creating our
own subdirectory under the debugfs root.

Another patch in this series will make the same change to the fusb302
driver, which also uses dev_name() (on the same device) for the debugfs
entry name. So we also prefix dev_name() with "tcpm-" here to avoid a
name conflict.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20190817184340.64086-1-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
 drivers/usb/typec/tcpm/tcpm.c | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index ec9460d9d330..166b28562395 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -19,6 +19,7 @@
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
+#include <linux/usb.h>
 #include <linux/usb/pd.h>
 #include <linux/usb/pd_ado.h>
 #include <linux/usb/pd_bdo.h>
@@ -571,17 +572,13 @@ static int tcpm_debug_show(struct seq_file *s, void *v)
 }
 DEFINE_SHOW_ATTRIBUTE(tcpm_debug);
 
-static struct dentry *rootdir;
-
 static void tcpm_debugfs_init(struct tcpm_port *port)
 {
-	mutex_init(&port->logbuffer_lock);
-	/* /sys/kernel/debug/tcpm/usbcX */
-	if (!rootdir)
-		rootdir = debugfs_create_dir("tcpm", NULL);
+	char name[NAME_MAX];
 
-	port->dentry = debugfs_create_file(dev_name(port->dev),
-					   S_IFREG | 0444, rootdir,
+	mutex_init(&port->logbuffer_lock);
+	snprintf(name, NAME_MAX, "tcpm-%s", dev_name(port->dev));
+	port->dentry = debugfs_create_file(name, S_IFREG | 0444, usb_debug_root,
 					   port, &tcpm_debug_fops);
 }
 
@@ -597,10 +594,6 @@ static void tcpm_debugfs_exit(struct tcpm_port *port)
 	mutex_unlock(&port->logbuffer_lock);
 
 	debugfs_remove(port->dentry);
-	if (list_empty(&rootdir->d_subdirs)) {
-		debugfs_remove(rootdir);
-		rootdir = NULL;
-	}
 }
 
 #else