Re: [PATCH] usb:cdns3: Fix for CV CH9 running with g_zero driver.

[Roger Quadros]

Pawel,

On 09/10/2019 06:58, Pawel Laszczak wrote:
> Hi,
>
> > Hi,
> >
> > Peter Chen <peter.chen@xxxxxxx> writes:
> > > On 19-10-07 07:39:11, Pawel Laszczak wrote:
> > > > Patch fixes issue with Halt Endnpoint Test observed
> > >
> > > %s/Endnpoint/Endpoint
> > >
> > > > during using g_zero
> > > > driver as DUT. Bug occurred only on some testing board.
> > >
> > > g_zero is legacy, please use configfs function source_sink or loopback
> > > instead.
> >
> > We still want fixes for those ;-)
>
> So, if my understanding is correct in new production systems
> using legacy gadget drivers is not recommended and we are not going to fix
> any more bugs there.

We can't really control who uses what. So we need to support legacy
drivers as well.

The issue detected by using g_zero is a controller driver issue and not an
issue with g_zero itself.

cheers,
-roger

> The legacy gadget drivers remains in the kernel only to support the old
> products.
>
> So because we introduce new driver we should not worry  about legacy
> gadget drivers.
>
> Is my understanding correct ?
>
> pawell
>   
> > > > Endpoint can defer transition to Halted state if endpoint has pending
> > > > requests.
> > >
> > > The implementation of halt handling is a little complicated, you may
> > > consider return -EAGAIN for functional stall through usb_ep_set_halt
> > > from function driver if the requests are pending, it doesn't need to
> > > defer such kinds of functional stall.
> >
> > -EAGAIN, IIRC is only supposed to be used for IN endpoint stalls.
> >
> > --
> > balbi

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