On Tue, Sep 07, 2021 at 09:09:35AM +0800, Linyu Yuan wrote:
> add a new list which link all usb_function at configfs layers,
> it means that after link a function a configuration,
> from configfs layer, we can still found all functions,
> it will allow trace all functions from configfs.
I am sorry, but I do not understand this paragraph. Can you try
rewording it?
>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
How did the kernel test robot report this? You are adding a new
function here, it is not a bug you are fixing, right?
> Signed-off-by: Linyu Yuan <quic_linyyuan@xxxxxxxxxxx>
> ---
> v2: fix unused cfg variable warning
> v3: add struct inside configfs.c
> v4: no change
> v5: lost v2 fix, add it again
>
> drivers/usb/gadget/configfs.c | 55 ++++++++++++++++++++++++-------------------
> 1 file changed, 31 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
> index 477e72a..5b2e6f9 100644
> --- a/drivers/usb/gadget/configfs.c
> +++ b/drivers/usb/gadget/configfs.c
> @@ -58,6 +58,11 @@ static inline struct gadget_info *to_gadget_info(struct config_item *item)
> return container_of(to_config_group(item), struct gadget_info, group);
> }
>
> +struct config_usb_function {
> + struct list_head list;
> + struct usb_function *f;
> +};
What lock protects this list?
> +
> struct config_usb_cfg {
> struct config_group group;
> struct config_group strings_group;
> @@ -420,7 +425,7 @@ static int config_usb_cfg_link(
> struct usb_function_instance *fi = container_of(group,
> struct usb_function_instance, group);
> struct usb_function_instance *a_fi;
> - struct usb_function *f;
> + struct config_usb_function *cf;
> int ret;
>
> mutex_lock(&gi->lock);
> @@ -438,21 +443,29 @@ static int config_usb_cfg_link(
> goto out;
> }
>
> - list_for_each_entry(f, &cfg->func_list, list) {
> - if (f->fi == fi) {
> + list_for_each_entry(cf, &cfg->func_list, list) {
> + if (cf->f->fi == fi) {
> ret = -EEXIST;
> goto out;
> }
> }
>
> - f = usb_get_function(fi);
> - if (IS_ERR(f)) {
> - ret = PTR_ERR(f);
> + cf = kzalloc(sizeof(*cf), GFP_KERNEL);
Why "kzalloc" and not "kmalloc"?
I don't understand why you are moving everything to a single list in the
system, what is wrong with the existing per-device one?
thanks,
greg k-h
