From patchwork Thu Oct 1 00:44:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thinh Nguyen X-Patchwork-Id: 297407 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=-10.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED 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 6EB45C4363D for ; Thu, 1 Oct 2020 00:44:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 286EC2137B for ; Thu, 1 Oct 2020 00:44:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=synopsys.com header.i=@synopsys.com header.b="RGPOXfy4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732234AbgJAAol (ORCPT ); Wed, 30 Sep 2020 20:44:41 -0400 Received: from smtprelay-out1.synopsys.com ([149.117.87.133]:55904 "EHLO smtprelay-out1.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730155AbgJAAok (ORCPT ); Wed, 30 Sep 2020 20:44:40 -0400 Received: from mailhost.synopsys.com (sv2-mailhost1.synopsys.com [10.205.2.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by smtprelay-out1.synopsys.com (Postfix) with ESMTPS id 1EEDFC08E7; Thu, 1 Oct 2020 00:44:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=synopsys.com; s=mail; t=1601513080; bh=w4bQMMPMytV5Fqto2kYUq5ZP20jsNlOdXC9UuB1FQB0=; h=Date:In-Reply-To:References:From:Subject:To:Cc:From; b=RGPOXfy4J/jJXe6W4dWXKAMEfi41122rh2B+GmsSpuXW8whbAinNxPoVs+rwy5agz 9pd55FtMs9/A/KElJ8ahN0WDMthhwzvwSJfw11XaGVNGSyay7X3UFP7BiP9xq+Uum3 29F5A2aRWs5nSEVtVJBiNzIvlH+aWAVbeOL1W1s/XhbxZQJUbhak5orMriYSklxYH6 ocmwuFHC4sRDaEhJQsRNFwzHt852jOILzAyLkDiAsdX2G22u5S5A0p8ZZegM6dErgb qXTvs0cYqwuR3kQlrVynSn5est6CKIUZU3iqm1fRNd/5Xkc7GdFg/Nv40oxOkQ3RfS paoUzEUsPhB8A== Received: from te-lab16 (nanobot.internal.synopsys.com [10.10.186.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mailhost.synopsys.com (Postfix) with ESMTPSA id E1949A00A0; Thu, 1 Oct 2020 00:44:38 +0000 (UTC) Received: by te-lab16 (sSMTP sendmail emulation); Wed, 30 Sep 2020 17:44:38 -0700 Date: Wed, 30 Sep 2020 17:44:38 -0700 Message-Id: In-Reply-To: References: X-SNPS-Relay: synopsys.com From: Thinh Nguyen Subject: [PATCH 4/4] usb: dwc3: gadget: Return early if no TRB update To: Felipe Balbi , Greg Kroah-Hartman , Thinh.Nguyen@synopsys.com, linux-usb@vger.kernel.org Cc: John Youn Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org If the transfer had already started and there's no TRB to update, then there's no need to go through __dwc3_gadget_kick_transfer(). There is no problem reissuing UPDATE_TRANSFER command. This change just saves the driver from doing a few operations. This happens when we run out of TRB and function driver still queues for more requests. Signed-off-by: Thinh Nguyen --- drivers/usb/dwc3/gadget.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index ff924656f690..da1f2ad2ad90 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1347,6 +1347,13 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep) starting = !(dep->flags & DWC3_EP_TRANSFER_STARTED); + /* + * If there's no new TRB prepared and we don't need to restart a + * transfer, there's no need to update the transfer. + */ + if (!ret && !starting) + return ret; + req = next_request(&dep->started_list); if (!req) { dep->flags |= DWC3_EP_PENDING_REQUEST;