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=-0.8 required=3.0 tests=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 91C2DC606B0 for ; Tue, 9 Jul 2019 10:28:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 72FEF2082A for ; Tue, 9 Jul 2019 10:28:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726091AbfGIK2d (ORCPT ); Tue, 9 Jul 2019 06:28:33 -0400 Received: from mail-ot1-f66.google.com ([209.85.210.66]:36931 "EHLO mail-ot1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726018AbfGIK2c (ORCPT ); Tue, 9 Jul 2019 06:28:32 -0400 Received: by mail-ot1-f66.google.com with SMTP id s20so19412177otp.4; Tue, 09 Jul 2019 03:28:32 -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=U4Ze+EBg1pxr4RvmQIS+6KLPYm2gsPa0r7l9E0VG4tg=; b=CXjMT5A3uOYjrn6TRV3OUi0EcW2q07yZkkMP+emhK0vam+BGdEOQhOeng0nNZaIt/s +QsmLSsdrQED0xNzZtvWUJQNqlBkw2lXr5LngPoEV52Rf63Pzke8T9H4vDyBbTwE1Mpt c7Ya8aoSk+04jyyYk7nfCNpAJE/+fSGPlfyBeIw6aLL1KzfBoSd/6QF1z9JBVgGv9iww eVBQzskHfWWPkMvzb4wZ2IScWIb19KzZTuBxvC66GUjL5+FLX94Zs6J/rz/9hMtxDoOC 7Vb31+bVbJC0WLSAm9hCitfhtVLGdoXDtrDytFkc7kndxHUqGi+jRH5wg2XaAO4b4PqH 20/Q== X-Gm-Message-State: APjAAAWoQ3QdsfnQOC+r5TZoVJGv8MmvEchYAmlTuTidjQT2Z0ezLgLD qXKskw+Tnj1RUHSY/Tgn7nEFLddlucpOk2DEP10= X-Google-Smtp-Source: APXvYqxFZQWNdaYg5Jvp6VDTI6ormIW150FFZQxe67AdnnbwRic7ntvpUSmHWfo8ekrM8Xcd8+9l/Jcljq9rAAt32Wg= X-Received: by 2002:a9d:7a90:: with SMTP id l16mr6703735otn.297.1562668112050; Tue, 09 Jul 2019 03:28:32 -0700 (PDT) MIME-Version: 1.0 References: <20190709095952.5666-1-geert+renesas@glider.be> <17f28f31-73e1-5170-a0d5-31ad9826defa@ideasonboard.com> In-Reply-To: From: Geert Uytterhoeven Date: Tue, 9 Jul 2019 12:28:21 +0200 Message-ID: Subject: Re: [PATCH] media: fdp1: Reduce FCP not found message level to debug To: Kieran Bingham Cc: Geert Uytterhoeven , Laurent Pinchart , Mauro Carvalho Chehab , Linux Media Mailing List , Linux-Renesas Content-Type: text/plain; charset="UTF-8" Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Kieran, On Tue, Jul 9, 2019 at 12:18 PM Kieran Bingham wrote: > On 09/07/2019 11:13, Geert Uytterhoeven wrote: > > On Tue, Jul 9, 2019 at 12:07 PM Kieran Bingham > > wrote: > >> On 09/07/2019 10:59, Geert Uytterhoeven wrote: > >>> When support for the IPMMU is not enabled, the FDP driver may be > >>> probe-deferred multiple times, causing several messages to be printed > >>> like: > >>> > >>> rcar_fdp1 fe940000.fdp1: FCP not found (-517) > >>> rcar_fdp1 fe944000.fdp1: FCP not found (-517) > >>> > >>> Fix this by reducing the message level to debug level, as is done in the > >>> VSP1 driver. > >> > >> Does the lack of IPMMU prevent the FDP1 being loaded entirely? > > > > No it doesn't. > > If CONFIG_IPMMU_VMSA=n, > > > > rcar_fdp1 fe940000.fdp1: FCP not found (-517) > > rcar_fdp1 fe944000.fdp1: FCP not found (-517) > > rcar_fdp1 fe940000.fdp1: FCP not found (-517) > > rcar_fdp1 fe944000.fdp1: FCP not found (-517) > > rcar_fdp1 fe940000.fdp1: FCP not found (-517) > > rcar_fdp1 fe944000.fdp1: FCP not found (-517) > > rcar_fdp1 fe940000.fdp1: Device registered as /dev/video8 > > rcar_fdp1 fe944000.fdp1: Device registered as /dev/video9 > > > > So the driver succeeds, eventually. > > > > If CONFIG_IPMMU_VMSA=y, it succeeds sooner: > > > > rcar_fdp1 fe940000.fdp1: Device registered as /dev/video0 > > rcar_fdp1 fe944000.fdp1: Device registered as /dev/video1 > > > > Always be prepared to handle -EPROBE_DEFER. > > On the basis that the driver is not prevented from loading, then the > message does indeed become more of a debug print. > > I wonder if it's better to print something different in the event of > EPROBE_DEFER vs another actual error preventing the loading of the > driver, but in either case if someone hits an issue they're likely to > start adding/enabling debug. That's why some driver suppress printing errors for -EPROBE_DEFER. > So, with that and a precedent for this change in VSP1, I'm happy here. > > Reviewed-by: Kieran Bingham Thanks! 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