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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 9DDB8C0650F for ; Tue, 30 Jul 2019 15:26:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7C5E72089E for ; Tue, 30 Jul 2019 15:26:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732375AbfG3P0D (ORCPT ); Tue, 30 Jul 2019 11:26:03 -0400 Received: from imap1.codethink.co.uk ([176.9.8.82]:50754 "EHLO imap1.codethink.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730358AbfG3P0D (ORCPT ); Tue, 30 Jul 2019 11:26:03 -0400 Received: from [167.98.27.226] (helo=[10.35.6.253]) by imap1.codethink.co.uk with esmtpsa (Exim 4.84_2 #1 (Debian)) id 1hsU0k-0000og-32; Tue, 30 Jul 2019 16:25:58 +0100 Subject: Re: [alsa-devel] [PATCH v2 3/3] ASoC: TDA7802: Add turn-on diagnostic routine To: Mark Brown Cc: Mark Rutland , devicetree@vger.kernel.org, alsa-devel@alsa-project.org, Charles Keepax , Kuninori Morimoto , Kirill Marinushkin , Cheng-Yi Chiang , Marco Felsch , Takashi Iwai , Annaliese McDermond , Liam Girdwood , Paul Cercueil , Vinod Koul , Rob Herring , Srinivas Kandagatla , linux-kernel@vger.kernel.org, Jerome Brunet References: <20190730120937.16271-1-thomas.preston@codethink.co.uk> <20190730120937.16271-4-thomas.preston@codethink.co.uk> <20190730141935.GF4264@sirena.org.uk> From: Thomas Preston Message-ID: <45156592-a90f-b4f8-4d30-9631c03f1280@codethink.co.uk> Date: Tue, 30 Jul 2019 16:25:56 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190730141935.GF4264@sirena.org.uk> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/07/2019 15:19, Mark Brown wrote: > On Tue, Jul 30, 2019 at 01:09:37PM +0100, Thomas Preston wrote: > >> + struct dentry *debugfs; >> + struct mutex diagnostic_mutex; >> +}; > > It is unclear what this mutex usefully protects, it only gets taken when > writing to the debugfs file to trigger this diagnostic mode but doesn't > do anything to control interactions with any other code path in the > driver. > If another process reads the debugfs node "diagnostic" while the turn-on diagnostic mode is running, this mutex prevents the second process restarting the diagnostics. This is redundant if debugfs reads are atomic, but I don't think they are. >> +static int run_turn_on_diagnostic(struct tda7802_priv *tda7802, u8 *status) >> +{ >> + struct device *dev = &tda7802->i2c->dev; >> + int err_status, err; >> + unsigned int val; >> + u8 state[NUM_IB]; > >> + /* We must wait 20ms for device to settle, otherwise diagnostics will >> + * not start and regmap poll will timeout. >> + */ >> + msleep(DIAGNOSTIC_SETTLE_MS); > > The comment and define might go out of sync... > Thanks, I will remove the 20ms but keep the comment here. >> + err = regmap_bulk_read(tda7802->regmap, TDA7802_DB1, status, 4); >> + if (err < 0) { >> + dev_err(dev, "Could not read channel status, %d\n", err); >> + goto diagnostic_restore; >> + } > > ...but here we use a magic number for the array size :( > Thanks, will update. >> +static int tda7802_diagnostic_show(struct seq_file *f, void *p) >> +{ >> + char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL); > > We neither use nor free buf? > >> +static int tda7802_probe(struct snd_soc_component *component) >> +{ >> + struct tda7802_priv *tda7802 = snd_soc_component_get_drvdata(component); >> + struct device *dev = &tda7802->i2c->dev; >> + int err; > > Why is this done at the component level? > Argh my bad, a previous iteration required the buf and component. I missed this, sorry for the noise. Thanks for feedback, I'll go back and tend to all of this.