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=-4.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no 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 1C384C4360C for ; Mon, 30 Sep 2019 07:00:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D7C0121A4A for ; Mon, 30 Sep 2019 07:00:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=googlemail.com header.i=@googlemail.com header.b="fdABa5sb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729355AbfI3HAJ (ORCPT ); Mon, 30 Sep 2019 03:00:09 -0400 Received: from mail-vs1-f66.google.com ([209.85.217.66]:37842 "EHLO mail-vs1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726858AbfI3HAJ (ORCPT ); Mon, 30 Sep 2019 03:00:09 -0400 Received: by mail-vs1-f66.google.com with SMTP id p13so6041387vsr.4; Mon, 30 Sep 2019 00:00:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=WPCu9sOB25lXthDF79C2tI3pqVlApVfxowlbJ7D2bJg=; b=fdABa5sb3wgC9qift36otR5o95WPE9hdVZ/CGRUd9rT5pM0CSYsv154TY19KyS4Ehy TbQZIscpyTFWTy3Qrr3dLEjRWZQVTnhzGt3CR9QQhtfuGaMxTdXCW0VqKyddZlSEDs+I y4LtwM1Eqpok0gOb29kA/omKAeBhPfJvzbXRFctvU9FGHcqwdYNexDm9ugMwONiwfHQN O5hK2u0R/f1cW6BDSxwZF00jnzZiH1hqtxGgk4tFRmOC8iwvebfp469wBX/4BumNBMhW K4jvKGvLB5ClCgSmK+mfSLTRYvaJxjFYFp8Dci7PrSD2fggsAywtQ4AP/yx9TwxpBTcO aGxw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WPCu9sOB25lXthDF79C2tI3pqVlApVfxowlbJ7D2bJg=; b=q/B9S8CLu3dwpkTAKoPDqRMYynyJNkxKQQYt3pP9viKST8SEabz7DV3HPNeVymntE6 2Lvrxm9QutyOvGdhGY6m4RfAMWAD/ziBTDptjs+sI1bIzcQF7xW5KJEUwsAaPj28/ORm ify54w2as1i+EGA5neSDqH05pkobDHeqSZcN32Idwp34s02Xr70fMHCXfknmVLx1UzXo inDdGsmq+Y5GXQWvZ5K02+AKmFuzP4AS5CHQ4XSez6XpJMTgD3bq8JYtzx9zX7mH1RVB 3qD4nIJLw+veiqwf3RTn0TWoE40lykf3crNvRyDJqx2/B2m1XdCrVJeTlSliRCOZcQ5H 4jVQ== X-Gm-Message-State: APjAAAVulf+YKr/pTdXI5KFYyTW9H+SCrF0k3G0pd+xCjFW+KUXJ+JjV OGZ2QamAoof7bXk/xxhyqEfv1Tw3fTsF8MQr1SQ= X-Google-Smtp-Source: APXvYqwlLkX6f9yRlFlinkuFmNZ1HqVjfgSj8PAsFaooE7maEiujWShYgybsI/sgKC1rHNGwVcoAR6KGjZToMb1vO9M= X-Received: by 2002:a67:6542:: with SMTP id z63mr9053529vsb.143.1569826808018; Mon, 30 Sep 2019 00:00:08 -0700 (PDT) MIME-Version: 1.0 References: <20190927151935.GD5610@atomide.com> <20190927155738.GF5610@atomide.com> In-Reply-To: From: Yegor Yefremov Date: Mon, 30 Sep 2019 08:59:51 +0200 Message-ID: Subject: Re: musb: cppi41: broken high speed FTDI functionality when connected to musb directly To: Tony Lindgren Cc: linux-omap@vger.kernel.org, vkoul@kernel.org, Bin Liu , linux-usb , Andrey Skvortsov , giulio.benetti@benettiengineering.com Content-Type: text/plain; charset="UTF-8" Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Sat, Sep 28, 2019 at 6:09 PM Yegor Yefremov wrote: > > On Fri, Sep 27, 2019 at 5:57 PM Tony Lindgren wrote: > > > > * Tony Lindgren [190927 15:20]: > > > * Yegor Yefremov [190927 12:31]: > > > > On Fri, Sep 27, 2019 at 10:18 AM Yegor Yefremov > > > > wrote: > > > > > > > > > > I was porting my system from 3.18/4.2 to 5.3. During this process I > > > > > noticed that FT4232 that is attached directly to musb is not working > > > > > correctly when opened for the first time: tx is working but nothing > > > > > can be received. On the second opening everything is working fine. > > > > > When the same chip is connected via a USB hub - everything is working > > > > > from the very beginning. > > > > > > > > > > I could reproduce this issue using BeagleBone Black with omap2plus_defconfig. > > > > > > > > > > # lsusb -t > > > > > +/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=musb-hdrc/1p, 480M > > > > > |__ Port 1: Dev 2, If 0, Class=, Driver=ftdi_sio, 480M > > > > > |__ Port 1: Dev 2, If 1, Class=, Driver=ftdi_sio, 480M > > > > > |__ Port 1: Dev 2, If 2, Class=, Driver=ftdi_sio, 480M > > > > > |__ Port 1: Dev 2, If 3, Class=, Driver=ftdi_sio, 480M > > > > > > > > > > git bisect revealed the following: > > > > > > > > > > fdea2d09b997ba4c86e7a707a5fac87c305f2131 is the first bad commit > > > > > commit fdea2d09b997ba4c86e7a707a5fac87c305f2131 > > > > > Author: Tony Lindgren > > > > > Date: Wed Aug 31 07:19:59 2016 -0700 > > > > > > > > > > dmaengine: cppi41: Add basic PM runtime support > > > > > > > > > > Let's keep the device enabled between cppi41_dma_issue_pending() > > > > > and dmaengine_desc_get_callback_invoke() and rely on the PM runtime > > > > > autoidle timeout elsewhere. > > > > > > > > > > As the PM runtime is for whole device, not for each channel, > > > > > we need to queue pending transfers if the device is PM runtime > > > > > suspended. Then we start the pending transfers in PM runtime > > > > > resume. > > > > > > > > > > Signed-off-by: Tony Lindgren > > > > > Signed-off-by: Vinod Koul > > > > > > > > > > :040000 040000 8cf92c09083541dfdee01cc2973e73ef520f4fb1 > > > > > a03c1a7ba8e723f7b503733c46edaa4141483265 M drivers > > > > > > > > > > Any idea? > > > > > > > > The problems can be reproduced with other FTDI chips like FT232R. > > > > > > > > Invoking "minicom -D /dev/ttyUSB0" and typing some characters is > > > > enough to reproduce the issue (just in case, hw flow control should be > > > > disabled). > > > > > > > > cp210x based converter is working without an issue. So only FTDI chips > > > > are affected so far. > > > > > > Hmm OK. Maybe this could be an issue where the FTDI chip takes > > > longer to enumerate and cppi41 is already suspended by then? > > > > > > At least we had a similar issue with commit ae4a3e028bb8 > > > ("dmaengine: cppi41: Fix runtime PM timeouts with USB mass > > > storage"). > > > > Looks like I'm unable to reproduce this with bbb and FT232R > > USB UART. > > > > I tried v5.3 with omap2plus_defconfig, then boot, load musb > > and ftdi-sio modules, then connect ftdi directly to bbb, > > and then run "minicom -D /dev/ttyUSB0" on bbb and it works > > just fine for me. > > > > I tried also rebooting the device inbetween in case it only > > happens on the first connect after boot but still no luck > > reproducing. > > Strange. I've used a loopback to check whether the characters will be echoed. > FTDI cable was connected all the time so that I could check RX right after boot. > Both Buildroot and OpenWrt rootfs's showed this behaviour. > > > Maybe try adding some debug prints to cppi41_runtime_suspend() > > and cppi41_runtime_resume() to see if gets runtime suspended > > too early? > > Will do on Mo. I've added the printks to both routines and the result is quite interesting. On the system with a directly attached FTDI both routines will be always invoked before (resume) and after (suspend) the test/minicom i.e. during the USB initialization. On the systems with a USB hub, these routines will be invoked only during the USB initialization and the last invocation is resume. During the test, there are no invocations. Regards, Yegor