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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 ABF5BC47083 for ; Mon, 31 May 2021 13:35:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 979AF61935 for ; Mon, 31 May 2021 13:35:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232455AbhEaNhB (ORCPT ); Mon, 31 May 2021 09:37:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:38860 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232588AbhEaNdK (ORCPT ); Mon, 31 May 2021 09:33:10 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EC6B0613F4; Mon, 31 May 2021 13:24:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1622467456; bh=kDdYKZEM5c2yqPsyjEYkReI62oz9TW0MrGZVYjyv3RY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=039OMWEdjn61ORqT38nDHaT6LKB0OejX4uzn3RBgxFHis9Pl5iR5uN/ksvcY5OSUG iVFJkbj+85yJgKq/aOVwJVrXtKnuedtzGRnPUShAv2WbRwTw8pEZ9DWuQWrS73p1vZ aO1fIN15t3HozV6FmnyV6sBBJR8BFQuqdjhEbxtQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Grzeschik , Felipe Balbi , Thinh Nguyen Subject: [PATCH 4.19 037/116] usb: dwc3: gadget: Properly track pending and queued SG Date: Mon, 31 May 2021 15:13:33 +0200 Message-Id: <20210531130641.424328314@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210531130640.131924542@linuxfoundation.org> References: <20210531130640.131924542@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Thinh Nguyen commit 25dda9fc56bd90d45f9a4516bcfa5211e61b4290 upstream. The driver incorrectly uses req->num_pending_sgs to track both the number of pending and queued SG entries. It only prepares the next request if the previous is done, and it doesn't update num_pending_sgs until there is TRB completion interrupt. This may starve the controller of more TRBs until the num_pending_sgs is decremented. Fix this by decrementing the num_pending_sgs after they are queued and properly track both num_mapped_sgs and num_queued_sgs. Fixes: c96e6725db9d ("usb: dwc3: gadget: Correct the logic for queuing sgs") Cc: Reported-by: Michael Grzeschik Tested-by: Michael Grzeschik Acked-by: Felipe Balbi Signed-off-by: Thinh Nguyen Link: https://lore.kernel.org/r/ba24591dbcaad8f244a3e88bd449bb7205a5aec3.1620874069.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc3/gadget.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1162,6 +1162,7 @@ static void dwc3_prepare_one_trb_sg(stru req->start_sg = sg_next(s); req->num_queued_sgs++; + req->num_pending_sgs--; /* * The number of pending SG entries may not correspond to the @@ -1169,7 +1170,7 @@ static void dwc3_prepare_one_trb_sg(stru * don't include unused SG entries. */ if (length == 0) { - req->num_pending_sgs -= req->request.num_mapped_sgs - req->num_queued_sgs; + req->num_pending_sgs = 0; break; } @@ -2361,15 +2362,15 @@ static int dwc3_gadget_ep_reclaim_trb_sg struct dwc3_trb *trb = &dep->trb_pool[dep->trb_dequeue]; struct scatterlist *sg = req->sg; struct scatterlist *s; - unsigned int pending = req->num_pending_sgs; + unsigned int num_queued = req->num_queued_sgs; unsigned int i; int ret = 0; - for_each_sg(sg, s, pending, i) { + for_each_sg(sg, s, num_queued, i) { trb = &dep->trb_pool[dep->trb_dequeue]; req->sg = sg_next(s); - req->num_pending_sgs--; + req->num_queued_sgs--; ret = dwc3_gadget_ep_reclaim_completed_trb(dep, req, trb, event, status, true); @@ -2392,7 +2393,7 @@ static int dwc3_gadget_ep_reclaim_trb_li static bool dwc3_gadget_ep_request_completed(struct dwc3_request *req) { - return req->num_pending_sgs == 0; + return req->num_pending_sgs == 0 && req->num_queued_sgs == 0; } static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep, @@ -2401,7 +2402,7 @@ static int dwc3_gadget_ep_cleanup_comple { int ret; - if (req->num_pending_sgs) + if (req->request.num_mapped_sgs) ret = dwc3_gadget_ep_reclaim_trb_sg(dep, req, event, status); else