Re: [PATCH] usb/core: Added devspec sysfs entry for devices behind usb hub

From: Vijay Kumar
Date: Wed Oct 05 2016 - 15:15:56 EST

On 10/4/2016 2:49 PM, Greg KH wrote:
On Tue, Oct 04, 2016 at 12:04:40PM -0700, Vijay Kumar wrote:
Grub finds incorrect of_node path for devices behind usb hub.
Added devspec sysfs entry for devices behind usb hub so that
right of_node path is returned during grub sysfs walk for these

Signed-off-by: Vijay Kumar <>

drivers/usb/core/sysfs.c | 15 +++++++++++++++
1 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index c953a0f..84d66d5 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -14,6 +14,7 @@
#include <linux/string.h>
#include <linux/usb.h>
#include <linux/usb/quirks.h>
+#include <linux/of.h>
#include "usb.h"
/* Active configuration fields */
@@ -104,6 +105,17 @@ static ssize_t bConfigurationValue_store(struct device *dev,
bConfigurationValue_show, bConfigurationValue_store);
+#ifdef CONFIG_OF
+static ssize_t devspec_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+ struct device_node *of_node = dev->of_node;
+ return sprintf(buf, "%s\n", of_node_full_name(of_node));
+static DEVICE_ATTR_RO(devspec);
Any way to do this without the #ifdef?
Thanks for your comment. I looked into it again and find that grub would
report ofpath incorrectly if CONFIG_OF not defined but devspec sysfs file exists.
I see pci-sysfs.c has also defines devspec in same way.

And you need to also update Documentation/ABI if you add a new sysfs

Sure, if you agree with my above comment then should I make Document/ABI
changes in a separate patch?