usb: cdc-wdm: adding list lookup indirection
Register all interfaces handled by this driver in a list, getting
rid of the dependency on usb_set_intfdata. This allows further
generalization and simplification of the probe/create functions.
This is needed to decouple wdm_open from the driver owning the
interface, and it also allows us to share all the code in
wdm_create with drivers unable to do usb_set_intfdata.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 4517930..46827373e 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -78,6 +78,8 @@
#define WDM_DEFAULT_BUFSIZE 256
static DEFINE_MUTEX(wdm_mutex);
+static DEFINE_SPINLOCK(wdm_device_list_lock);
+static LIST_HEAD(wdm_device_list);
/* --- method tables --- */
@@ -112,10 +114,39 @@
struct work_struct rxwork;
int werr;
int rerr;
+
+ struct list_head device_list;
};
static struct usb_driver wdm_driver;
+/* return intfdata if we own the interface, else look up intf in the list */
+static struct wdm_device *wdm_find_device(struct usb_interface *intf)
+{
+ struct wdm_device *desc = NULL;
+
+ spin_lock(&wdm_device_list_lock);
+ list_for_each_entry(desc, &wdm_device_list, device_list)
+ if (desc->intf == intf)
+ break;
+ spin_unlock(&wdm_device_list_lock);
+
+ return desc;
+}
+
+static struct wdm_device *wdm_find_device_by_minor(int minor)
+{
+ struct wdm_device *desc = NULL;
+
+ spin_lock(&wdm_device_list_lock);
+ list_for_each_entry(desc, &wdm_device_list, device_list)
+ if (desc->intf->minor == minor)
+ break;
+ spin_unlock(&wdm_device_list_lock);
+
+ return desc;
+}
+
/* --- callbacks --- */
static void wdm_out_callback(struct urb *urb)
{
@@ -275,6 +306,9 @@
static void cleanup(struct wdm_device *desc)
{
+ spin_lock(&wdm_device_list_lock);
+ list_del(&desc->device_list);
+ spin_unlock(&wdm_device_list_lock);
kfree(desc->sbuf);
kfree(desc->inbuf);
kfree(desc->orq);
@@ -532,11 +566,11 @@
struct wdm_device *desc;
mutex_lock(&wdm_mutex);
- intf = usb_find_interface(&wdm_driver, minor);
- if (!intf)
+ desc = wdm_find_device_by_minor(minor);
+ if (!desc)
goto out;
- desc = usb_get_intfdata(intf);
+ intf = desc->intf;
if (test_bit(WDM_DISCONNECTING, &desc->flags))
goto out;
file->private_data = desc;
@@ -639,6 +673,7 @@
desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
if (!desc)
goto out;
+ INIT_LIST_HEAD(&desc->device_list);
mutex_init(&desc->rlock);
mutex_init(&desc->wlock);
spin_lock_init(&desc->iuspin);
@@ -715,16 +750,17 @@
desc
);
- usb_set_intfdata(intf, desc);
+ spin_lock(&wdm_device_list_lock);
+ list_add(&desc->device_list, &wdm_device_list);
+ spin_unlock(&wdm_device_list_lock);
+
rv = usb_register_dev(intf, &wdm_class);
if (rv < 0)
- goto err2;
+ goto err;
else
dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
out:
return rv;
-err2:
- usb_set_intfdata(intf, NULL);
err:
cleanup(desc);
return rv;
@@ -785,8 +821,8 @@
unsigned long flags;
usb_deregister_dev(intf, &wdm_class);
+ desc = wdm_find_device(intf);
mutex_lock(&wdm_mutex);
- desc = usb_get_intfdata(intf);
/* the spinlock makes sure no new urbs are generated in the callbacks */
spin_lock_irqsave(&desc->iuspin, flags);
@@ -810,7 +846,7 @@
#ifdef CONFIG_PM
static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
{
- struct wdm_device *desc = usb_get_intfdata(intf);
+ struct wdm_device *desc = wdm_find_device(intf);
int rv = 0;
dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
@@ -860,7 +896,7 @@
#ifdef CONFIG_PM
static int wdm_resume(struct usb_interface *intf)
{
- struct wdm_device *desc = usb_get_intfdata(intf);
+ struct wdm_device *desc = wdm_find_device(intf);
int rv;
dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
@@ -874,7 +910,7 @@
static int wdm_pre_reset(struct usb_interface *intf)
{
- struct wdm_device *desc = usb_get_intfdata(intf);
+ struct wdm_device *desc = wdm_find_device(intf);
/*
* we notify everybody using poll of
@@ -898,7 +934,7 @@
static int wdm_post_reset(struct usb_interface *intf)
{
- struct wdm_device *desc = usb_get_intfdata(intf);
+ struct wdm_device *desc = wdm_find_device(intf);
int rv;
clear_bit(WDM_RESETTING, &desc->flags);