[PATCH 15/18] staging: usbip: trigger driver probing after unbinding from usbip-host

Valentina Manea
2014-03-08T12:54:33Z

A sysfs attribute is used to announce kernel space that a
new driver probing session should be triggered for the just
unbinded device.

In order to have the address of struct device associated to this
USB device, a new member has been added to struct bus_id_priv.

Signed-off-by: Valentina Manea <valentina.manea.m@gmail.com>
---
drivers/staging/usbip/stub.h | 1 +
drivers/staging/usbip/stub_dev.c | 1 +
drivers/staging/usbip/stub_main.c | 39 ++++++++++++++++++++++
drivers/staging/usbip/userspace/src/usbip_unbind.c | 17 ++++++++--
4 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/usbip/stub.h b/drivers/staging/usbip/stub.h
index 82e539a..266e2b0 100644
--- a/drivers/staging/usbip/stub.h
+++ b/drivers/staging/usbip/stub.h
@@ -86,6 +86,7 @@ struct bus_id_priv {
char status;
int interf_count;
struct stub_device *sdev;
+ struct usb_device *udev;
char shutdown_busid;
};

diff --git a/drivers/staging/usbip/stub_dev.c b/drivers/staging/usbip/stub_dev.c
index 1bd13cf..ee899f0 100644
--- a/drivers/staging/usbip/stub_dev.c
+++ b/drivers/staging/usbip/stub_dev.c
@@ -386,6 +386,7 @@ static int stub_probe(struct usb_device *udev)
/* set private data to usb_device */
dev_set_drvdata(&udev->dev, sdev);
busid_priv->sdev = sdev;
+ busid_priv->udev = udev;

err = stub_add_files(&udev->dev);
if (err) {
diff --git a/drivers/staging/usbip/stub_main.c b/drivers/staging/usbip/stub_main.c
index bd7b83a..9c5832a 100644
--- a/drivers/staging/usbip/stub_main.c
+++ b/drivers/staging/usbip/stub_main.c
@@ -19,6 +19,7 @@

#include <linux/string.h>
#include <linux/module.h>
+#include <linux/device.h>

#include "usbip_common.h"
#include "stub.h"
@@ -187,6 +188,34 @@ static ssize_t store_match_busid(struct device_driver *dev, const char *buf,
static DRIVER_ATTR(match_busid, S_IRUSR | S_IWUSR, show_match_busid,
store_match_busid);

+static ssize_t rebind_store(struct device_driver *dev, const char *buf,
+ size_t count)
+{
+ int ret;
+ int len;
+ struct bus_id_priv *bid;
+
+ /* buf length should be less that BUSID_SIZE */
+ len = strnlen(buf, BUSID_SIZE);
+
+ if (!(len < BUSID_SIZE))
+ return -EINVAL;
+
+ bid = get_busid_priv(buf);
+ if (!bid)
+ return -ENODEV;
+
+ ret = device_attach(&bid->udev->dev);
+ if (ret < 0) {
+ dev_err(&bid->udev->dev, "rebind failed\n");
+ return ret;
+ }
+
+ return count;
+}
+
+static DRIVER_ATTR_WO(rebind);
+
static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead)
{
struct stub_priv *priv, *tmp;
@@ -267,6 +296,13 @@ static int __init usbip_host_init(void)
goto err_create_file;
}

+ ret = driver_create_file(&stub_driver.drvwrap.driver,
+ &driver_attr_rebind);
+ if (ret) {
+ pr_err("driver_create_file failed\n");
+ goto err_create_file;
+ }
+
pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
return ret;

@@ -282,6 +318,9 @@ static void __exit usbip_host_exit(void)
driver_remove_file(&stub_driver.drvwrap.driver,
&driver_attr_match_busid);

+ driver_remove_file(&stub_driver.drvwrap.driver,
+ &driver_attr_rebind);
+
/*
* deregister() calls stub_disconnect() for all devices. Device
* specific data is cleared in stub_disconnect().
diff --git a/drivers/staging/usbip/userspace/src/usbip_unbind.c b/drivers/staging/usbip/userspace/src/usbip_unbind.c
index 7180dbe..a4a496c 100644
--- a/drivers/staging/usbip/userspace/src/usbip_unbind.c
+++ b/drivers/staging/usbip/userspace/src/usbip_unbind.c
@@ -44,8 +44,10 @@ static int unbind_device(char *busid)
char bus_type[] = "usb";
int rc, ret = -1;

- char attr_name[] = "unbind";
+ char unbind_attr_name[] = "unbind";
char unbind_attr_path[SYSFS_PATH_MAX];
+ char rebind_attr_name[] = "rebind";
+ char rebind_attr_path[SYSFS_PATH_MAX];

struct udev *udev;
struct udev_device *dev;
@@ -71,7 +73,7 @@ static int unbind_device(char *busid)
/* Unbind device from driver. */
snprintf(unbind_attr_path, sizeof(unbind_attr_path), "%s/%s/%s/%s/%s/%s",
SYSFS_MNT_PATH, SYSFS_BUS_NAME, bus_type, SYSFS_DRIVERS_NAME,
- USBIP_HOST_DRV_NAME, attr_name);
+ USBIP_HOST_DRV_NAME, unbind_attr_name);

rc = write_sysfs_attribute(unbind_attr_path, busid, strlen(busid));
if (rc < 0) {
@@ -86,6 +88,17 @@ static int unbind_device(char *busid)
goto err_close_udev;
}

+ /* Trigger new probing. */
+ snprintf(rebind_attr_path, sizeof(unbind_attr_path), "%s/%s/%s/%s/%s/%s",
+ SYSFS_MNT_PATH, SYSFS_BUS_NAME, bus_type, SYSFS_DRIVERS_NAME,
+ USBIP_HOST_DRV_NAME, rebind_attr_name);
+
+ rc = write_sysfs_attribute(rebind_attr_path, busid, strlen(busid));
+ if (rc < 0) {
+ err("error rebinding");
+ goto err_close_udev;
+ }
+
ret = 0;
info("unbind device on busid %s: complete", busid);

--
1.8.1.2