From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thinh Nguyen , Felipe Balbi Subject: [PATCH 4.13 002/160] usb: dwc3: ep0: fix DMA starvation by assigning req->trb on ep0 Date: Tue, 10 Oct 2017 21:48:50 +0200 Message-Id: <20171010190548.870552558@linuxfoundation.org> In-Reply-To: <20171010190548.690912997@linuxfoundation.org> References: <20171010190548.690912997@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Felipe Balbi commit 55168470835688e5da5828cdcf1b1498d7baadb1 upstream. If we don't assign a TRB to ep0 requests, we won't be able to unmap the request later on resulting in starvation of DMA resources. Fixes: 4a71fcb8ac5f ("usb: dwc3: gadget: only unmap requests from DMA if mapped") Reported-by: Thinh Nguyen Tested-by: Thinh Nguyen Signed-off-by: Felipe Balbi Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc3/ep0.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/usb/dwc3/ep0.c +++ b/drivers/usb/dwc3/ep0.c @@ -990,6 +990,8 @@ static void __dwc3_ep0_do_control_data(s DWC3_TRBCTL_CONTROL_DATA, true); + req->trb = &dwc->ep0_trb[dep->trb_enqueue - 1]; + /* Now prepare one extra TRB to align transfer size */ dwc3_ep0_prepare_one_trb(dep, dwc->bounce_addr, maxpacket - rem, @@ -1015,6 +1017,8 @@ static void __dwc3_ep0_do_control_data(s DWC3_TRBCTL_CONTROL_DATA, true); + req->trb = &dwc->ep0_trb[dep->trb_enqueue - 1]; + /* Now prepare one extra TRB to align transfer size */ dwc3_ep0_prepare_one_trb(dep, dwc->bounce_addr, 0, DWC3_TRBCTL_CONTROL_DATA, @@ -1029,6 +1033,9 @@ static void __dwc3_ep0_do_control_data(s dwc3_ep0_prepare_one_trb(dep, req->request.dma, req->request.length, DWC3_TRBCTL_CONTROL_DATA, false); + + req->trb = &dwc->ep0_trb[dep->trb_enqueue]; + ret = dwc3_ep0_start_trans(dep); }