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USB: total removal of multithreaded probing in usb 

The whole approach is simply wrong.  Forking a thread means that
  - errors are ignored
  - locking is ignored

Doing this correctly would require major surgery for questionable benefit.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Oliver Neukum 2007-01-11 14:35:50 +01:00 committed by Greg Kroah-Hartman
parent 66e56ce75e
commit 3ede760f0e
1 changed files with 21 additions and 43 deletions
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64
drivers/usb/core/hub.c
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@ -87,9 +87,6 @@ static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);
static struct task_struct *khubd_task;
/* multithreaded probe logic */
static int multithread_probe = 0;
/* cycle leds on hubs that aren't blinking for attention */
static int blinkenlights = 0;
module_param (blinkenlights, bool, S_IRUGO);
@ -1256,9 +1253,28 @@ static inline void show_string(struct usb_device *udev, char *id, char *string)
static int __usb_port_suspend(struct usb_device *, int port1);
#endif
static int __usb_new_device(void *void_data)
/**
* usb_new_device - perform initial device setup (usbcore-internal)
* @udev: newly addressed device (in ADDRESS state)
*
* This is called with devices which have been enumerated, but not yet
* configured. The device descriptor is available, but not descriptors
* for any device configuration. The caller must have locked either
* the parent hub (if udev is a normal device) or else the
* usb_bus_list_lock (if udev is a root hub). The parent's pointer to
* udev has already been installed, but udev is not yet visible through
* sysfs or other filesystem code.
*
* It will return if the device is configured properly or not. Zero if
* the interface was registered with the driver core; else a negative
* errno value.
*
* This call is synchronous, and may not be used in an interrupt context.
*
* Only the hub driver or root-hub registrar should ever call this.
*/
int usb_new_device(struct usb_device *udev)
{
struct usb_device *udev = void_data;
int err;
/* Lock ourself into memory in order to keep a probe sequence
@ -1375,44 +1391,6 @@ fail:
goto exit;
}
/**
* usb_new_device - perform initial device setup (usbcore-internal)
* @udev: newly addressed device (in ADDRESS state)
*
* This is called with devices which have been enumerated, but not yet
* configured. The device descriptor is available, but not descriptors
* for any device configuration. The caller must have locked either
* the parent hub (if udev is a normal device) or else the
* usb_bus_list_lock (if udev is a root hub). The parent's pointer to
* udev has already been installed, but udev is not yet visible through
* sysfs or other filesystem code.
*
* The return value for this function depends on if the
* multithread_probe variable is set or not. If it's set, it will
* return a if the probe thread was successfully created or not. If the
* variable is not set, it will return if the device is configured
* properly or not. interfaces, in sysfs); else a negative errno value.
*
* This call is synchronous, and may not be used in an interrupt context.
*
* Only the hub driver or root-hub registrar should ever call this.
*/
int usb_new_device(struct usb_device *udev)
{
struct task_struct *probe_task;
int ret = 0;
if (multithread_probe) {
probe_task = kthread_run(__usb_new_device, udev,
"usb-probe-%s", udev->devnum);
if (IS_ERR(probe_task))
ret = PTR_ERR(probe_task);
} else
ret = __usb_new_device(udev);
return ret;
}
static int hub_port_status(struct usb_hub *hub, int port1,
u16 *status, u16 *change)
{