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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,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 959FFC433E1 for ; Wed, 8 Jul 2020 13:29:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 72E6E2078B for ; Wed, 8 Jul 2020 13:29:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=megous.com header.i=@megous.com header.b="JJlJUi+b" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729294AbgGHN31 (ORCPT ); Wed, 8 Jul 2020 09:29:27 -0400 Received: from vps.xff.cz ([195.181.215.36]:51668 "EHLO vps.xff.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728148AbgGHN30 (ORCPT ); Wed, 8 Jul 2020 09:29:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megous.com; s=mail; t=1594214964; bh=8N9bH83BZfSgEFYUIHwb06OwlfkSojJ4iISr/5Xqob8=; h=Date:From:To:Cc:Subject:References:X-My-GPG-KeyId:From; b=JJlJUi+bNmDQomRx+37m/rE4iJQhTBtYpUFCn4VDLVeJuxyyu3V3dBpWxiX8cBRLN GgSx5w2iaOnOryftkEVBYBM4d43Bd90Oh/868O3SxJipxc1VLXg+T4aJznBM9PNZfT wt3JZfK9taYEOvEKkjI4nL65UZvJ2dvgkVj/M0N0= Date: Wed, 8 Jul 2020 15:29:24 +0200 From: =?utf-8?Q?Ond=C5=99ej?= Jirman To: Maxime Ripard Cc: linux-sunxi@googlegroups.com, Vasily Khoruzhick , Yangtao Li , Zhang Rui , Daniel Lezcano , Amit Kucheria , Chen-Yu Tsai , "open list:ALLWINNER THERMAL DRIVER" , "moderated list:ARM/Allwinner sunXi SoC support" , open list Subject: Re: [PATCH] thermal: sun8i: Be loud when probe fails Message-ID: <20200708132924.r6f5id2evprhybec@core.my.home> Mail-Followup-To: =?utf-8?Q?Ond=C5=99ej?= Jirman , Maxime Ripard , linux-sunxi@googlegroups.com, Vasily Khoruzhick , Yangtao Li , Zhang Rui , Daniel Lezcano , Amit Kucheria , Chen-Yu Tsai , "open list:ALLWINNER THERMAL DRIVER" , "moderated list:ARM/Allwinner sunXi SoC support" , open list References: <20200708105527.868987-1-megous@megous.com> <20200708122542.73o3lbhgvbdw5c4z@gilmour.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200708122542.73o3lbhgvbdw5c4z@gilmour.lan> X-My-GPG-KeyId: EBFBDDE11FB918D44D1F56C1F9F0A873BE9777ED Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Hello Maxime, On Wed, Jul 08, 2020 at 02:25:42PM +0200, Maxime Ripard wrote: > Hi, > > On Wed, Jul 08, 2020 at 12:55:27PM +0200, Ondrej Jirman wrote: > > I noticed several mobile Linux distributions failing to enable the > > thermal regulation correctly, because the kernel is silent > > when thermal driver fails to probe. Add enough error reporting > > to debug issues and warn users in case thermal sensor is failing > > to probe. > > > > Failing to notify users means, that SoC can easily overheat under > > load. > > > > Signed-off-by: Ondrej Jirman > > --- > > drivers/thermal/sun8i_thermal.c | 55 ++++++++++++++++++++++++++------- > > 1 file changed, 43 insertions(+), 12 deletions(-) > > > > diff --git a/drivers/thermal/sun8i_thermal.c b/drivers/thermal/sun8i_thermal.c > > index 74d73be16496..9065e79ae743 100644 > > --- a/drivers/thermal/sun8i_thermal.c > > +++ b/drivers/thermal/sun8i_thermal.c > > @@ -287,8 +287,12 @@ static int sun8i_ths_calibrate(struct ths_device *tmdev) > > > > calcell = devm_nvmem_cell_get(dev, "calibration"); > > if (IS_ERR(calcell)) { > > + dev_err(dev, "Failed to get calibration nvmem cell (%ld)\n", > > + PTR_ERR(calcell)); > > + > > if (PTR_ERR(calcell) == -EPROBE_DEFER) > > return -EPROBE_DEFER; > > + > > The rest of the patch makes sense, but we should probably put the error > message after the EPROBE_DEFER return so that we don't print any extra > noise that isn't necessarily useful I thought about that, but in this case this would have helped, see my other e-mail. Though lack of "probe success" message may be enough for me, to debug the issue, I'm not sure the user will notice that a message is missing, while he'll surely notice if there's a flood of repeated EPROBE_DEFER messages. And people run several distros for 3-4 months without anyone noticing any issues and that thermal regulation doesn't work. So it seems that lack of a success message is not enough. Other solution may be to select CONFIG_NVMEM_SUNXI_SID if this driver is enabled. That may get rid of this error scenario of waiting infinitely for calibration data with EPROBE_DEFER. And other potential EPROBE_DEFER sources will probably be quite visible even without this driver telling the user. So this message may not be necessary in that case. thank you and regards, o. > Maxime