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=-2.5 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT 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 4CC1CC6778F for ; Wed, 25 Jul 2018 20:03:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0C89620843 for ; Wed, 25 Jul 2018 20:03:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0C89620843 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731122AbeGYVQj (ORCPT ); Wed, 25 Jul 2018 17:16:39 -0400 Received: from mail-io0-f194.google.com ([209.85.223.194]:35754 "EHLO mail-io0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729529AbeGYVQj (ORCPT ); Wed, 25 Jul 2018 17:16:39 -0400 Received: by mail-io0-f194.google.com with SMTP id w11-v6so7370644iob.2; Wed, 25 Jul 2018 13:03:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=d1Cp+bH2LbHimams80Agj70VeUhrDXkgDOc9KRuROAw=; b=UIWaH4PogUg7+YeoKb7CDMIL71ViEcCUipO0qy2n4lXcF92svaosJNMxtvvOzTw/DL I8iheHfS/N7nFu+cUEExWhQhqoN7Wf3vnTfx40feYP82bpUsDBag5xFS91GWzHIMsmae I4g5OsZgF0B4pFqf2XK7fiXxD9fc9OBNrIicfHM7POuYkAakU9X4szLELRsRhwlYN5CK JUHfqT+bSo7lE3CN6h1mw8CyB184egc299DJHi6NLSeJXfFug5YAo/czCLFxLYK7lxXc Trs+nlDMoVQ0sUPbBNWZqe+S5RfPg0uU8BvsR1aFGTgPPFxzTuJFBQcdKVnCZ9OzevYq tM1Q== X-Gm-Message-State: AOUpUlG6zpG8TnfBjUtnvImHZux/DbrSJpce7ssdxFTYRuvsQUD9aEBP ES4TI95FBEJVkqbiFihEsQ== X-Google-Smtp-Source: AAOMgpe3Cii7xyn69Fz5/lOXUu4UbcUFWNsJxNlxBhICzkIfMIPic45gbQtjKL++K/pIFxOFbHei5A== X-Received: by 2002:a6b:e619:: with SMTP id g25-v6mr17103529ioh.42.1532549006135; Wed, 25 Jul 2018 13:03:26 -0700 (PDT) Received: from localhost ([24.51.61.72]) by smtp.gmail.com with ESMTPSA id x94-v6sm2953767ita.18.2018.07.25.13.03.25 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 25 Jul 2018 13:03:25 -0700 (PDT) Date: Wed, 25 Jul 2018 14:03:25 -0600 From: Rob Herring To: Anurag Kumar Vulisha Cc: gregkh@linuxfoundation.org, mark.rutland@arm.com, balbi@kernel.org, v.anuragkumar@gmail.com, linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] usb: dwc3: core: Add quirk for enabling AutoRetry feature in the controller Message-ID: <20180725200325.GA21007@rob-hp-laptop> References: <1532168920-3269-1-git-send-email-anurag.kumar.vulisha@xilinx.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1532168920-3269-1-git-send-email-anurag.kumar.vulisha@xilinx.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jul 21, 2018 at 03:58:40PM +0530, Anurag Kumar Vulisha wrote: > By default when core sees any transaction error(CRC or overflow) > it replies with terminating retry ACK (Retry=1 and Nump == 0). > Enabling this Auto Retry feature in controller, on seeing any > transaction errors makes the core to send an non-terminating ACK > transaction packet (that is, ACK TP with Retry=1 and Nump != 0). > Doing so will give controller a chance to recover from the error > condition. > > Signed-off-by: Anurag Kumar Vulisha > --- > Documentation/devicetree/bindings/usb/dwc3.txt | 5 +++++ > drivers/usb/dwc3/core.c | 16 ++++++++++++++++ > drivers/usb/dwc3/core.h | 6 ++++++ > 3 files changed, 27 insertions(+) > > diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt > index 7f13ebe..2ba2bc2 100644 > --- a/Documentation/devicetree/bindings/usb/dwc3.txt > +++ b/Documentation/devicetree/bindings/usb/dwc3.txt > @@ -94,6 +94,11 @@ Optional properties: > this and tx-thr-num-pkt-prd to a valid, non-zero value > 1-16 (DWC_usb31 programming guide section 1.2.3) to > enable periodic ESS TX threshold. > + - snps,enable_auto_retry: Set to enable Auto retry Feature to make the s/_/-/ > + controller operating in Host mode on seeing transaction > + errors(CRC errors or internal overrun scenerios) on IN > + transfers to reply to the device with a non-terminating > + retry ACK (i.e, an ACK TP with Retry=1 & Nump != 0) Seems like the property is unnecessary. When would you not want this retry behavior? Why not just enable unconditionally in the driver? Rob