Messages in this thread | | | Date | Mon, 24 Nov 2014 19:09:39 -0600 | From | Felipe Balbi <> | Subject | Re: [PATCH] usb: musb: core: Disable the Interrupts till BABBLE is fully handled |
| |
On Mon, Nov 24, 2014 at 09:56:28PM +0100, Sebastian Andrzej Siewior wrote: > On 11/24/2014 09:39 PM, Peter Stuge wrote: > > Felipe Balbi wrote: > >>>> A babble only occurs when > >>>> the device side tries to move data without the host asking for anything. > >>> > >>> It also occurs if the device moves more than packet_size bytes. Not > >>> really helping, I know… > >> > >> hmm, why would the device move more than wMaxPacketSize at a time ? > > > > Some devices are buggy. > > for instance if the device comes out of resume and the clock is not yet > stable but the device sends data. That is not the case here, but an > example :)
that would be a bug on clk driver, it shouldn't return control to the user until clk *is* stable :-)
> I *think* for some reason the host did not really receive ep0 > set_config request as planned. And device's answer is probably then > interpreted as data which is not expected (as Felipe said "device side > tries to move data without the host asking for anything").
that's definitely a bug, unfortunately I can't think of any Erratum right now.
> >> That's certainly babble :-) > > > > Certainly! But musb shouldn't fall over or lock up because of it, > > should it? > > No and the patch fixes the issue. The strange thing is that it only > happens on the same device. Not if you connect host<->device with two > boards.
probably some crap going on within the interconnect when both instances are used.
-- balbi [unhandled content-type:application/pgp-signature] | |