On Wed, Sep 27, 2023 at 01:54:34AM +0530, Krishna Kurapati PSSNV wrote:
>
>
> On 9/27/2023 1:36 AM, Krishna Kurapati PSSNV wrote:
> > > > drivers/usb/gadget/udc/core.c | 23 +++++++++++++++++++----
> > > > 1 file changed, 19 insertions(+), 4 deletions(-)
> > > >
> > > > static void vbus_event_work(struct work_struct *work)
> > > > @@ -1604,12 +1608,23 @@ static int gadget_bind_driver(struct
> > > > device *dev)
> > > > }
> > > > usb_gadget_enable_async_callbacks(udc);
> > > > udc->allow_connect = true;
> > > > - usb_udc_connect_control_locked(udc);
> > > > + ret = usb_udc_connect_control_locked(udc);
> > > > + if (ret) {
> > > > + mutex_unlock(&udc->connect_lock);
> > > > + goto err_connect_control;
> > > > + }
> > > > +
> > > > mutex_unlock(&udc->connect_lock);
> > > > kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
> > > > return 0;
> > > > + err_connect_control:
> > > > + usb_gadget_disable_async_callbacks(udc);
> > > > + if (gadget->irq)
> > > > + synchronize_irq(gadget->irq);
> > > > + usb_gadget_udc_stop_locked(udc);
> > >
> > > Not good -- usb_gadget_udc_stop_locked() expects you to be holding
> > > udc->connect_lock, but you just dropped the lock! Also, you never set
> > > udc->allow_connect back to false.
> > >
> > > You should move the mutex_unlock() call from inside the "if" statement
> > > to down here, and add a line for udc->allow_connect.
> > >
> >
> > Hi Alan,
> >
> > Thanks for the review. Will push v5 addressing the changes.
> >
> >
> Hi Alan,
>
> I tried out the following diff:
>
> - usb_udc_connect_control_locked(udc);
> + ret = usb_udc_connect_control_locked(udc);
> + if (ret)
> + goto err_connect_control;
> +
> mutex_unlock(&udc->connect_lock);
>
> kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
> return 0;
>
> + err_connect_control:
> + udc->allow_connect = false;
> + usb_gadget_disable_async_callbacks(udc);
> + if (gadget->irq)
> + synchronize_irq(gadget->irq);
> + usb_gadget_udc_stop_locked(udc);
> + mutex_unlock(&udc->connect_lock);
> +
>
> If I clear UDC and fail dwc3 soft reset on purpose, I see UDC_store failing:
>
> #echo a600000.usb > /sys/kernel/config/usb_gadget/g1/UDC
> [ 127.394087] dwc3 a600000.usb: request 000000003f43f907 was not queued to
> ep0out
> [ 127.401637] udc a600000.usb: failed to start g1: -110
> [ 127.406841] configfs-gadget.g1: probe of gadget.0 failed with error -110
> [ 127.413809] UDC core: g1: couldn't find an available UDC or it's busy
>
> The same output came when I tested v4 as well. Every time soft_reset would
> fail when I try to write to UDC, UDC_store fails and above log will come up.
Isn't that what you want? I thought the whole purpose of this patch was
to make it so that configfs would realize when
usb_udc_connect_control_locked() had failed. So you should be happy
that the log shows a failure occurred.
> Can you help confirm if the diff above is proper as I don't see any diff in
> the logs in v4 and about to push v5.
"Diff in the logs in v4"? What does that mean? A diff is a comparison
between two text files (often between before-and-after versions of a
source code file). Why would you expect a diff to show up in the logs?
This revised patch looks okay to me.
Alan Stern
