From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1347C282C8 for ; Mon, 28 Jan 2019 17:02:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AC88421741 for ; Mon, 28 Jan 2019 17:02:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548694921; bh=1wqeTZawMrcWaDe0DxpY5wEZUO4leMv2fBwt7THyKG4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JiPUFNYD+LwN1pVBQGEWbkbgpoPTVn7smLWAxw1k7L0OG/4yssvMUAzf6u5TkrDb5 y1s8D72pSAFe7H7kohTstxfgpaPogj9U77qd+QpYnMH0gd9LSBeo2plZIzo9r6WcAh FzPDwYjMj9yIt9gbdbEJmQ5jbBmOae8uMXKGiRBY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387684AbfA1QO6 (ORCPT ); Mon, 28 Jan 2019 11:14:58 -0500 Received: from mail.kernel.org ([198.145.29.99]:44472 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387664AbfA1QO4 (ORCPT ); Mon, 28 Jan 2019 11:14:56 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B69A321741; Mon, 28 Jan 2019 16:14:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548692095; bh=1wqeTZawMrcWaDe0DxpY5wEZUO4leMv2fBwt7THyKG4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xGylmqc3YRHn3TQ7Pw9aJW0TQy0S8IOAjEhrRr+S4DzP3+HzHbJuWNEk1KP6FwpaZ veaZJoZk79E3uUUbOIEIUKMP1ofkmOTEOP0dSulDrgBSZDXIzwqgFvWZrgGJGwpUbl XsfsPUsVvhinFQ1j32dV1TijnDsspbEPfIwUDsys= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Anurag Kumar Vulisha , Felipe Balbi , Sasha Levin , linux-usb@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 065/170] usb: dwc3: Correct the logic for checking TRB full in __dwc3_prepare_one_trb() Date: Mon, 28 Jan 2019 11:10:15 -0500 Message-Id: <20190128161200.55107-65-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190128161200.55107-1-sashal@kernel.org> References: <20190128161200.55107-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Anurag Kumar Vulisha [ Upstream commit b7a4fbe2300a8965ea760c7e871507b84aea17f6 ] Availability of TRB's is calculated using dwc3_calc_trbs_left(), which determines total available TRB's based on the HWO bit set in a TRB. In the present code, __dwc3_prepare_one_trb() is called with a TRB which needs to be prepared for transfer. This __dwc3_prepare_one_trb() calls dwc3_calc_trbs_left() to determine total available TRBs and set IOC bit if the total available TRBs are zero. Since the present working TRB (which is passed as an argument to __dwc3_prepare_one_trb() ) doesn't yet have the HWO bit set before calling dwc3_calc_trbs_left(), there are chances that dwc3_calc_trbs_left() wrongly calculates this present working TRB as free(since the HWO bit is not yet set) and returns the total available TRBs as greater than zero (including the present working TRB). This could be a problem. This patch corrects the above mentioned problem in __dwc3_prepare_one_trb() by increementing the dep->trb_enqueue at the last (after preparing the TRB) instead of increementing at the start and setting the IOC bit only if the total available TRBs returned by dwc3_calc_trbs_left() is 1 . Since we are increementing the dep->trb_enqueue at the last, the present working TRB is also considered as available by dwc3_calc_trbs_left() and non zero value is returned . So, according to the modified logic, when the total available TRBs is equal to 1 that means the total available TRBs in the pool are 0. Signed-off-by: Anurag Kumar Vulisha Reviewed-by: Thinh Nguyen Tested-by: Tejas Joglekar Signed-off-by: Felipe Balbi Signed-off-by: Sasha Levin --- drivers/usb/dwc3/gadget.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index b8704c0678f9..59284acd8013 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -888,8 +888,6 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb, struct usb_gadget *gadget = &dwc->gadget; enum usb_device_speed speed = gadget->speed; - dwc3_ep_inc_enq(dep); - trb->size = DWC3_TRB_SIZE_LENGTH(length); trb->bpl = lower_32_bits(dma); trb->bph = upper_32_bits(dma); @@ -968,7 +966,7 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb, } if ((!no_interrupt && !chain) || - (dwc3_calc_trbs_left(dep) == 0)) + (dwc3_calc_trbs_left(dep) == 1)) trb->ctrl |= DWC3_TRB_CTRL_IOC; if (chain) @@ -979,6 +977,8 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb, trb->ctrl |= DWC3_TRB_CTRL_HWO; + dwc3_ep_inc_enq(dep); + trace_dwc3_prepare_trb(dep, trb); } -- 2.19.1