On Fri, 14 May 2010 tom.leiming@xxxxxxxxx wrote:
> From: Ming Lei <tom.leiming@xxxxxxxxx>
>
> For root-hub devices, we don't support the 'remove' action,
> but deconfiguration may cause root-hub to stop work even
> usb_remove_device returns failure.
>
> Considered it is very similar to remove a usb device by
> usb_remove_device only, compared with physical disconnection processing.
>
> There are no races conditions found if only usb_remove_device is
> called to do 'remove' action without deconfiguration, so remove
> the deconfiguration to fix it.
>
> Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
> ---
> drivers/usb/core/sysfs.c | 7 ++-----
> 1 files changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
> index 06863be..5a2add3 100644
> --- a/drivers/usb/core/sysfs.c
> +++ b/drivers/usb/core/sysfs.c
> @@ -568,12 +568,9 @@ static ssize_t usb_remove_store(struct device *dev,
> int rc = 0;
>
> usb_lock_device(udev);
> - if (udev->state != USB_STATE_NOTATTACHED) {
> -
> - /* To avoid races, first unconfigure and then remove */
> - usb_set_configuration(udev, -1);
> + if (udev->state != USB_STATE_NOTATTACHED)
> rc = usb_remove_device(udev);
> - }
> +
Instead of changing what the code does in the normal case, why not just
prevent it from being used with root hubs? Add an initial test:
/* Removing root hubs makes no sense */
if (!udev->parent)
return -EINVAL;
usb_lock_device(udev) ...
Alan Stern
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
