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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 14D48C43381 for ; Mon, 4 Mar 2019 16:25:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF94720823 for ; Mon, 4 Mar 2019 16:25:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="aIwaJLX8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727303AbfCDQZO (ORCPT ); Mon, 4 Mar 2019 11:25:14 -0500 Received: from mail-oi1-f195.google.com ([209.85.167.195]:38345 "EHLO mail-oi1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726409AbfCDQZO (ORCPT ); Mon, 4 Mar 2019 11:25:14 -0500 Received: by mail-oi1-f195.google.com with SMTP id q81so4290658oic.5; Mon, 04 Mar 2019 08:25:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=yTnTWpeeE+CiV9lF7EKLxXS6uvkQq6oVoshcbDcQFHE=; b=aIwaJLX8fAJARmQAXKN+Bt026UwSWI0hT4PfxUBE9vM0XHl5WUdnES5ij/+/67qDht neLoWMziY9HEnAetneJSvwPVVnD/NkGt+1KGmopv4lJw0mv3C1Vm05cBaGjgUVKES3BA cq478rdxNjbXBirYSbAYOvZvNfLsgWetZrEfYlJ/Ys+iNr2Laqy3Sl6LfgQdWV53LmNU +L4mbvMqxHXzI6xiVqvqynngAUNRRPVXj525zv+PfOouLwhUm/cjhtO8r6HMAEv9KHJ2 s4b6ojkEJzZ6uz4P8M2hhTXZxP6VqkJA/M3JQqU3prSQAindqQhLZuY5DyBiOcGfGpmb 9KzQ== 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=yTnTWpeeE+CiV9lF7EKLxXS6uvkQq6oVoshcbDcQFHE=; b=Bo4LphJil1dUhjSc2lDMIW/b1Ex07GPsLrY+XxXRPy0ZRx/nf2smkz5ty8Dxmkdbri oHOv04hI+zqe9nArn4MI+2TBYbIIY6Hb1NtmJTIPOVwpxrV/lli0n21jNrof4ZmjsSG8 mi25/dKuelPdWqQUjxEwGStV1y2nuJ8dKxI2Ua95bYzuHzQQ3j1Az6DebLe4etUCSIIA OM+WLvd5LBUZccD7K+V4QRKVpKXpqEIqzPQMOMYRBZhBzQ7Au9ERq0k9byWHZ3XFBUd5 1UBjL4I1VPAfIonBWpO5f/GJscL+VLbgEeioZeaAWvhtDDIFgUnf1Q3RMs8QFDCavjqz xiTw== X-Gm-Message-State: AHQUAubiwPXNv/aRctHTe5HQjwopEbb4IKNdtZPnv2kRW6kwerVrbASG C/ha74kTKGLFG+Olp4Qwe2yEaVVSutfa3i/5ZdqH4jTz X-Google-Smtp-Source: AHgI3IZfY4xH72Ud2Z0jZvklOuLruer5i2WjjxuLztJVqvarSKJKS0zOtWgMpVxCDfws/KAq3fVkNvtaAVFUSWOUPlM= X-Received: by 2002:aca:3142:: with SMTP id x63mr11980855oix.92.1551716712873; Mon, 04 Mar 2019 08:25:12 -0800 (PST) MIME-Version: 1.0 References: <42dbbd7568e4216a320c6fd617bd91c1ee045af0.1551037168.git.bobbyeshleman@gmail.com> <20190303143813.3b5a3f22@archlinux> In-Reply-To: <20190303143813.3b5a3f22@archlinux> From: Sven Van Asbroeck Date: Mon, 4 Mar 2019 11:25:01 -0500 Message-ID: Subject: Re: [PATCH v2 1/3] iio: light: Add driver for ap3216c To: Jonathan Cameron Cc: Robert Eshleman , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Linux Kernel Mailing List , linux-iio@vger.kernel.org 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 On Sun, Mar 3, 2019 at 9:38 AM Jonathan Cameron wrote: > > Hmm. Just been thinking a bit about the events on here and wondered > if it is possible to mask them through careful use of the threshold > values - i.e. can we stop the hardware generating the interrupts for > the ones we don't want. It would be unusual for hardware to be > designed where this wasn't possible. Excellent point! People with power / battery constraints take a dim view of receiving interrupts when no-one wants them. So disabling them in h/w is definitely the way to go, if possible. And yes, this also makes a non-issue of thresh_en visibility concerns, if any. > > Alternatively if you have a scope or equivalent to verify if it is doing > these as a multi byte read and working that would be even better. > It is not uncommon for hardware to implement fairly standard i2c features > like this and not document them because they weren't what the test code > the docs writer got given does! (may not be true here of course) Or alternatively, the current chip rev supports undocumented multi-reads, and the next revision silently drops support, thereby breaking the driver... Been there, done that, got the T-shirt :(