Hi, On Tue, Sep 09, 2014 at 03:20:58PM +0200, François MULLER wrote: > Hi all, > > I've backported some commits to my kernel (3.4) to get gadget state > tracking. > > I think that I missed something or there is a small error on this one that > hasn't been spotted: > > http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=49401f4169c0e5a1b38f1a676d6f12eecaf77485 > > ----------------- > +void usb_gadget_set_state(struct usb_gadget *gadget, > + enum usb_device_state state) > +{ > + gadget->state = state; > + sysfs_notify(&gadget->dev.kobj, NULL, "status"); > +} > ----------------- > > The sysfs_notify is done on the gadget kobject and the sysfs group is under > the udc kobject : > > ----------------- > static struct attribute *usb_udc_attrs[] = { > (...) > + &dev_attr_state.attr, > > int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget > *gadget, > (...) > udc->dev.groups = usb_udc_attr_groups; > ----------------- > > To make it work correctly we need to do the sysfs_notify on the udc kobject > too. > We've done this using this following patch : > > ----------------- > diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c > index 7d8d839..03e9f49 100644 > --- a/drivers/usb/gadget/udc-core.c > +++ b/drivers/usb/gadget/udc-core.c > @@ -129,8 +129,18 @@ static inline int usb_gadget_start(struct usb_gadget > *gadget, > static void usb_gadget_state_work(struct work_struct *work) > { > struct usb_gadget *gadget = work_to_gadget(work); > + struct usb_udc *udc = NULL; > + > + mutex_lock(&udc_lock); > + list_for_each_entry(udc, &udc_list, list) > + if (udc->gadget == gadget) > + goto found; > + udc = NULL; > +found: > + mutex_unlock(&udc_lock); > > - sysfs_notify(&gadget->dev.kobj, NULL, "state"); > + if(udc) > + sysfs_notify(&udc->dev.kobj, NULL, "state"); > } > > void usb_gadget_set_state(struct usb_gadget *gadget, > ----------------- > > If there is something I missed, please tell me. you haven't missed anything, you're correct. Do you want to send this in a proper patch format so it's included in all supported kernels which are affected by this bug ? Please have a read at Documentation/CodingStyle, Documentation/SubmittingPatches, Documentation/SubmitChecklist and Documentation/stable_kernel_rules.txt With that, you should be able to send a patch in the proper format. From a code standpoint, you really found a good bug :-) Don't forget to add: Fixes: 49401f4 (usb: gadget: introduce gadget state tracking) Cc: <stable@xxxxxxxxxxxxxxx> # v3.10+ to your commit log, right above your Signed-off-by line. cheers -- balbi
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