| Message ID | 20211126110954.2677627-4-neal_liu@aspeedtech.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/3] usb: aspeed-vhub: add qualifier descriptor | expand |
> -----Original Message----- > From: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Sent: Tuesday, November 30, 2021 7:49 AM > To: Neal Liu <neal_liu@aspeedtech.com>; Felipe Balbi <balbi@kernel.org>; > Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Joel Stanley > <joel@jms.id.au>; Andrew Jeffery <andrew@aj.id.au>; Cai Huoqing > <caihuoqing@baidu.com>; Tao Ren <rentao.bupt@gmail.com>; Julia Lawall > <julia.lawall@inria.fr>; kernel test robot <lkp@intel.com>; Sasha Levin > <sashal@kernel.org>; linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org; > linux-arm-kernel@lists.infradead.org; linux-aspeed@lists.ozlabs.org > Cc: BMC-SW <BMC-SW@aspeedtech.com> > Subject: Re: [PATCH 3/3] usb: aspeed-vhub: fix ep0 OUT ack received wrong > length issue > > On Fri, 2021-11-26 at 19:09 +0800, Neal Liu wrote: > > > > diff --git a/drivers/usb/gadget/udc/aspeed-vhub/ep0.c > > b/drivers/usb/gadget/udc/aspeed-vhub/ep0.c > > index 74ea36c19b1e..bea9cbb191a2 100644 > > --- a/drivers/usb/gadget/udc/aspeed-vhub/ep0.c > > +++ b/drivers/usb/gadget/udc/aspeed-vhub/ep0.c > > @@ -251,6 +251,13 @@ static void ast_vhub_ep0_do_receive(struct > > ast_vhub_ep *ep, struct ast_vhub_req > > len = remain; > > rc = -EOVERFLOW; > > } > > + > > + /* HW return wrong data len */ > > + if (len < ep->ep.maxpacket && len != remain) { > > + EPDBG(ep, "using expected data len instead\n"); > > + len = remain; > > + } > > + > > Wow, that is a nasty hw bug ! Patch looks good, I had to swap some of that > logic back into my brain but it looks like it won't break any normal case :-) > > Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> > > Cheers, > Ben. Thanks for your review. -Neal
diff --git a/drivers/usb/gadget/udc/aspeed-vhub/ep0.c b/drivers/usb/gadget/udc/aspeed-vhub/ep0.c index 74ea36c19b1e..bea9cbb191a2 100644 --- a/drivers/usb/gadget/udc/aspeed-vhub/ep0.c +++ b/drivers/usb/gadget/udc/aspeed-vhub/ep0.c @@ -251,6 +251,13 @@ static void ast_vhub_ep0_do_receive(struct ast_vhub_ep *ep, struct ast_vhub_req len = remain; rc = -EOVERFLOW; } + + /* HW return wrong data len */ + if (len < ep->ep.maxpacket && len != remain) { + EPDBG(ep, "using expected data len instead\n"); + len = remain; + } + if (len && req->req.buf) memcpy(req->req.buf + req->req.actual, ep->buf, len); req->req.actual += len;
If multiple devices in vhub are enumerated simultaneously, ep0 OUT ack might received wrong data length. Using expected data length instead. Signed-off-by: Neal Liu <neal_liu@aspeedtech.com> --- drivers/usb/gadget/udc/aspeed-vhub/ep0.c | 7 +++++++ 1 file changed, 7 insertions(+)