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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 5EDDCC47256 for ; Wed, 6 May 2020 21:01:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3FF4D20A8B for ; Wed, 6 May 2020 21:01:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="S+Y03lcb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729511AbgEFVB3 (ORCPT ); Wed, 6 May 2020 17:01:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55154 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1728535AbgEFVB3 (ORCPT ); Wed, 6 May 2020 17:01:29 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0D45C061A0F; Wed, 6 May 2020 14:01:28 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id t9so1607150pjw.0; Wed, 06 May 2020 14:01:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=1PrjJgczo6pwbhVfqtxrYxW7d4ubPdJ5akMV/EdzMO8=; b=S+Y03lcbRfS4M03fe9S1xwCVxAew8y69Mno1QzyJ/cD0m8jpGdJg8JIK2yqt//5s/q TKDuS4ScDuolgCXocIib85qeZn8viFjl3ZwYbLZ74AjJPOIww2Z+qq2ecwqNJaWYqvcU 2tfQvU8RJYpdhGsK03ZHN8a5gWrGQ2KT7tuiGdxLy/PtyCLeWYjt5xTYChefFsgTRQrh muaj8qoHgMIXaZSNgBd+7u0w4dVpkTHvL+WHSG8rHfvH+rKqyr+oYqER7vb9+ndZ6qIc j5NleHcXh5HGSEkyRv99dn7fWAMNJmGKm0khoWYkhnzH7IWcqWnaY3/iPeCO8FZpzvyI bh4g== 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=1PrjJgczo6pwbhVfqtxrYxW7d4ubPdJ5akMV/EdzMO8=; b=m3k3dPqmeDthwy7mluqMlagKCoHjHkvAkZ/hjmYOGGk/mzjeMAXVMcZGivxBDRU9ND SPOJMjBtZqcjvQS4i7qvvmnsWLQvazPU0EEKG13CrGj5qCSMnw6CehvuciUyidc8xlus WWrHj6a0ER70+HxQDHBA888eu/kIeyPUUI7hLuxva01SjIl0zh3LQhQr4gQyRUPHJmCd WTs1L2KECtT0WkVnv5K5XyvGKkEOKux2wI7Kp82TNz3GA7lbpC1Ws229H01OMtEPHnmb JmdkcEV9WBvaBL4q7FKLNMrFEYPH0ZMRqJhTYVjC9OiqkS3XbnK/k0TvJ/RBORLgjWFc mCWQ== X-Gm-Message-State: AGi0PuZOTL1hs2Lt/uY6yKRcjTvh/7SBpjt5JoVMk2Guz1gRPNGuknFb fFc3zCPYiNLH4u1RhtLeGiriElCJHsnCUnoJ1vM= X-Google-Smtp-Source: APiQypKdZjzSlTyFQ/T9CUwUL01Xf79l+ICWYHY1E+4V+NAKRwMIyNo2UDSTCSmbRJOkOJSrbKREYvBDA7BlnuxgR6E= X-Received: by 2002:a17:902:6901:: with SMTP id j1mr9830320plk.255.1588798888435; Wed, 06 May 2020 14:01:28 -0700 (PDT) MIME-Version: 1.0 References: <20200430111258.6091-1-alcooperx@gmail.com> <20200430111258.6091-4-alcooperx@gmail.com> <20200505110036.GB93160@kroah.com> In-Reply-To: From: Andy Shevchenko Date: Thu, 7 May 2020 00:01:16 +0300 Message-ID: Subject: Re: [PATCH v6 3/4] usb: ehci: Add new EHCI driver for Broadcom STB SoC's To: Alan Cooper Cc: Greg Kroah-Hartman , ": Linux Kernel Mailing List" , Alan Stern , BCM Kernel Feedback , DTML , Krzysztof Kozlowski , USB list , Mathias Nyman , Rob Herring , Yoshihiro Shimoda , Andy Shevchenko Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 6, 2020 at 11:23 PM Alan Cooper wrote: > On Tue, May 5, 2020 at 7:00 AM Greg Kroah-Hartman > wrote: > > On Thu, Apr 30, 2020 at 07:12:57AM -0400, Al Cooper wrote: ... > > > + /* Hook the hub control routine to work around a bug */ > > > > What bug? This feels wrong. > > The bug is explained in a comment above the ehci_brcm_hub_control() > routine as follows: > /* > * ehci_brcm_hub_control > * Intercept echi-hcd request to complete RESUME and align it to the start > * of the next microframe. > * If RESUME is complete too late in the microframe, host controller > * detects babble on suspended port and resets the port afterwards. > * This s/w workaround allows to avoid this problem. > * See SWLINUX-1909 for more details > */ > I'll remove the internal bug tracking reference from the comment. I guess you may leave the internal bug reference. I can tell from my experience that's hard to understand what was going on in the driver in years perspective. It will help whoever in this company have a chance to look after the driver. -- With Best Regards, Andy Shevchenko