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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 1AF17C04AB4 for ; Tue, 14 May 2019 08:28:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E93ED20675 for ; Tue, 14 May 2019 08:28:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726974AbfENI2s (ORCPT ); Tue, 14 May 2019 04:28:48 -0400 Received: from mail-ua1-f67.google.com ([209.85.222.67]:34085 "EHLO mail-ua1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726109AbfENI2s (ORCPT ); Tue, 14 May 2019 04:28:48 -0400 Received: by mail-ua1-f67.google.com with SMTP id 7so1786842uah.1; Tue, 14 May 2019 01:28:47 -0700 (PDT) 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=/NA3o69AVedwbrS8I/JNFCMoka6aSRYx6sOSkm7j+ZY=; b=sWgbCysasls5T0fl83xIYjpsrFQUwdFB9c00tAyeFdNssQL6P4oHoo5COXUm+f/6A1 ayG7O8p9Tgf2fUn8N6rzoQnSZUePC4/JzJQYlfE/ZbTkgMRO2yeAAefz8nq6YSGZ43UT W40o3xXh9d9538IE0NrDii59lG6ogBdYvkRa2IauaAG5xJ7uc1KuS/rQOnixZrAe7IkV 1tUZYKZKemMSpYaD4ie9Edhd7FQdxBOUJtgHIEWJauyGGuCGGMc0SuzOceh1ZnGBbSPC gOkQ68MKkpGA/wWNks4CnVKO7XO27I/VfMbgbocICTjRhe0O03pSpCDWYas++gLnEgYC tp7g== X-Gm-Message-State: APjAAAVvpSQ02Mb7kYjA24EDNaHNWCNtrKlOwY3H1QsyyQlsrRNOd5wH bc6ZGzQf0B8iRuPZ2FmWsH67XBV8TXG3PqFXj04= X-Google-Smtp-Source: APXvYqwdcU+/txalebspsx4VOD+EnsWOMl3ldpM6w0yNu5aBmbUhQ7DwUL4yoq5BDqRktbvDVPuCHNLpcUJd09+lby0= X-Received: by 2002:ab0:45e9:: with SMTP id u96mr4671687uau.75.1557822526733; Tue, 14 May 2019 01:28:46 -0700 (PDT) MIME-Version: 1.0 References: <1557762446-23811-1-git-send-email-george_davis@mentor.com> In-Reply-To: <1557762446-23811-1-git-send-email-george_davis@mentor.com> From: Geert Uytterhoeven Date: Tue, 14 May 2019 10:28:34 +0200 Message-ID: Subject: Re: [PATCH v2] serial: sh-sci: disable DMA for uart_console To: "George G. Davis" Cc: Eugeniu Rosca , Simon Horman , Wolfram Sang , Greg Kroah-Hartman , Jiri Slaby , "open list:SERIAL DRIVERS" , open list , Chris Brandt , Ulrich Hecht , Andy Lowe , Linux-Renesas , OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS , Magnus Damm , Rob Herring , Mark Rutland , stable 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 Hi George, On Mon, May 13, 2019 at 5:48 PM George G. Davis wrote: > As noted in commit 84b40e3b57ee ("serial: 8250: omap: Disable DMA for > console UART"), UART console lines use low-level PIO only access functions > which will conflict with use of the line when DMA is enabled, e.g. when > the console line is also used for systemd messages. So disable DMA > support for UART console lines. > > Fixes: https://patchwork.kernel.org/patch/10929511/ I don't think this is an appropriate reference, as it points to a patch that was never applied. As the problem has basically existed forever, IMHO no Fixes tag is needed. > Reported-by: Michael Rodin > Tested-by: Eugeniu Rosca > Reviewed-by: Simon Horman > Reviewed-by: Wolfram Sang > Cc: stable@vger.kernel.org > Signed-off-by: George G. Davis > --- > v2: Clarify comment regarding DMA support on kernel console, > add {Tested,Reviewed}-by:, and Cc: linux-stable lines. Thanks for the update! Reviewed-by: Geert Uytterhoeven Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: Re: [PATCH v2] serial: sh-sci: disable DMA for uart_console Date: Tue, 14 May 2019 10:28:34 +0200 Message-ID: References: <1557762446-23811-1-git-send-email-george_davis@mentor.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <1557762446-23811-1-git-send-email-george_davis@mentor.com> Sender: linux-kernel-owner@vger.kernel.org To: "George G. Davis" Cc: Eugeniu Rosca , Simon Horman , Wolfram Sang , Greg Kroah-Hartman , Jiri Slaby , "open list:SERIAL DRIVERS" , open list , Chris Brandt , Ulrich Hecht , Andy Lowe , Linux-Renesas , OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS , Magnus Damm , Rob Herring , Mark Rutland , stable List-Id: devicetree@vger.kernel.org Hi George, On Mon, May 13, 2019 at 5:48 PM George G. Davis wrote: > As noted in commit 84b40e3b57ee ("serial: 8250: omap: Disable DMA for > console UART"), UART console lines use low-level PIO only access functions > which will conflict with use of the line when DMA is enabled, e.g. when > the console line is also used for systemd messages. So disable DMA > support for UART console lines. > > Fixes: https://patchwork.kernel.org/patch/10929511/ I don't think this is an appropriate reference, as it points to a patch that was never applied. As the problem has basically existed forever, IMHO no Fixes tag is needed. > Reported-by: Michael Rodin > Tested-by: Eugeniu Rosca > Reviewed-by: Simon Horman > Reviewed-by: Wolfram Sang > Cc: stable@vger.kernel.org > Signed-off-by: George G. Davis > --- > v2: Clarify comment regarding DMA support on kernel console, > add {Tested,Reviewed}-by:, and Cc: linux-stable lines. Thanks for the update! Reviewed-by: Geert Uytterhoeven Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds