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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 839D6C606B0 for ; Tue, 9 Jul 2019 10:18:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 546D720665 for ; Tue, 9 Jul 2019 10:18:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="RQjTsNmB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726025AbfGIKSU (ORCPT ); Tue, 9 Jul 2019 06:18:20 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:36228 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725989AbfGIKSU (ORCPT ); Tue, 9 Jul 2019 06:18:20 -0400 Received: from [192.168.0.20] (cpc89242-aztw30-2-0-cust488.18-1.cable.virginm.net [86.31.129.233]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id B27A356A; Tue, 9 Jul 2019 12:18:18 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1562667499; bh=MdeSSN04nWT3RBeeVMJNe63i4/7XzdLMYS3PNR5i6Ow=; h=Reply-To:Subject:To:Cc:References:From:Date:In-Reply-To:From; b=RQjTsNmBX8Oc4sLsSugHRBi421RN/OH6U6Pe3zXKOtXSAv2+fJ2wlbMIQQ8aRyba8 qeqZ8NdZHnYj8odUdfp+FY1xRvIpMwzlDDzByHEq7FDh0gfN6HM6YiE4P52pIUnaRj qTTImR3O1GfiqYzJOfF7hTCfgceWkQPmsGXVJmUQ= Reply-To: kieran.bingham+renesas@ideasonboard.com Subject: Re: [PATCH] media: fdp1: Reduce FCP not found message level to debug To: Geert Uytterhoeven Cc: Geert Uytterhoeven , Laurent Pinchart , Mauro Carvalho Chehab , Linux Media Mailing List , Linux-Renesas References: <20190709095952.5666-1-geert+renesas@glider.be> <17f28f31-73e1-5170-a0d5-31ad9826defa@ideasonboard.com> From: Kieran Bingham Organization: Ideas on Board Message-ID: Date: Tue, 9 Jul 2019 11:18:16 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org Hi Geert, On 09/07/2019 11:13, Geert Uytterhoeven wrote: > Hi Kieran, > > 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. > > Gr{oetje,eeting}s, 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. So, with that and a precedent for this change in VSP1, I'm happy here. Reviewed-by: Kieran Bingham > > Geert >