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=-7.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 BC907C432BE for ; Mon, 30 Aug 2021 23:20:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9634560F6B for ; Mon, 30 Aug 2021 23:20:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238842AbhH3XVU (ORCPT ); Mon, 30 Aug 2021 19:21:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59138 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230185AbhH3XVU (ORCPT ); Mon, 30 Aug 2021 19:21:20 -0400 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E032C061575 for ; Mon, 30 Aug 2021 16:20:26 -0700 (PDT) Received: by mail-pj1-x102d.google.com with SMTP id d5so4766016pjx.2 for ; Mon, 30 Aug 2021 16:20:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=j46bRfPm7kUb/CtmHZFmvXNYwCSK1nOeCFtanpOutjM=; b=aC4TzO5CxN50l+GI30QoBfSu5ko9B38P91tbBy4sr9QgQhovoJQxg1bPjG5sVq1Cht kDYvF4q6XfGgdJ6GhoHca4zshDJW3TJS1csHQzWh0Y7DzAHOJgQmaYLMBoCBxl3drnrc n7dIDiTHEA4kUuI6mGorXZbobLdqfZ0QgtloACgold5yn/TMgPvWa3lXDKaQelqA/PHF rZRCkItbivzHH7IzAtx/rsljJEtvynuC/KJIT2+By84ED3LQW5MyebKlkijFgFd2lW7p 9JlDKw8Hvy5V+kWz4TFaqeyhxsiOYB295RCDrBV4yCZT7zHZUSTsJtXmNZ+AdBZ3sqGD nnOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=j46bRfPm7kUb/CtmHZFmvXNYwCSK1nOeCFtanpOutjM=; b=DiXX4jFBTcmXeXeF11LNgYa17akKavynlW6QpVmKu4Tfgnz/HXs8V2xQiMSkEuj2nR Af5Wo9LoTvE4snqqdH2mltBxz9eQAV2zZQC8vdi61F/G/34NqWSOIKDNIuGCide716EY IagRu1Zv6RTROhtJk4Zlq1Qy3UJbP85Bw1dYgmg2cYBnPgcMLANIfRE6JGyHSzRMr8bk TiUdfI3h+zQ+1+yC79FZQIwiA6+DxvagdTDIFBx3TvDawfQC050V/r7dXqNMwkKrxpL2 ub/pMtZeJGqUuWji5sie5W2585VrfbcNDSpoAQ2MSC2v+R274Meto3innwYOAJ3L6TbG LJFA== X-Gm-Message-State: AOAM533REXkeMTYpm7sDCnQ2WoWcDW8NNqQNpa5ffQr2SgNW/ntqe2Tj VbUYq5olBRxBsXa5pVaXGho= X-Google-Smtp-Source: ABdhPJwvCJTHEpjsUNT8AebnA+AbqMEKTCCQqx37ThWQnN0hB0f4We9cI7EoB+7ffabGC5OXg3FdRw== X-Received: by 2002:a17:90a:ea08:: with SMTP id w8mr1699675pjy.218.1630365625579; Mon, 30 Aug 2021 16:20:25 -0700 (PDT) Received: from google.com ([2620:15c:202:201:771a:afc8:2e96:23dd]) by smtp.gmail.com with ESMTPSA id m3sm8845144pfo.94.2021.08.30.16.20.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Aug 2021 16:20:24 -0700 (PDT) Date: Mon, 30 Aug 2021 16:20:22 -0700 From: Dmitry Torokhov To: Marek Vasut Cc: linux-input@vger.kernel.org, ch@denx.de, Joe Hung , Luca Hsu Subject: Re: [PATCH v2 2/3] Input: ili210x - export ili251x version details via sysfs Message-ID: References: <20210827211258.318618-1-marex@denx.de> <20210827211258.318618-2-marex@denx.de> <991280e5-fd54-75d5-d2f2-bb2673303881@denx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <991280e5-fd54-75d5-d2f2-bb2673303881@denx.de> Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org On Tue, Aug 31, 2021 at 01:02:57AM +0200, Marek Vasut wrote: > On 8/30/21 11:01 PM, Dmitry Torokhov wrote: > > [...] > > > > @@ -351,6 +360,108 @@ static int ili251x_firmware_update_resolution(struct device *dev) > > > return 0; > > > } > > > +static ssize_t ili251x_firmware_version_show(struct device *dev, > > > + struct device_attribute *attr, > > > + char *buf) > > > +{ > > > + struct i2c_client *client = to_i2c_client(dev); > > > + struct ili210x *priv = i2c_get_clientdata(client); > > > + u8 fw[8]; > > > + int ret; > > > + > > > + /* Get firmware version */ > > > + mutex_lock(&priv->lock); > > > + ret = priv->chip->read_reg(client, REG_FIRMWARE_VERSION, > > > + &fw, sizeof(fw)); > > > + mutex_unlock(&priv->lock); > > > > Could we query firmware version and mode at probe time (and also later > > after firmware update attempt) so that we do not need to introduce > > locking against interrupt handler? > > This is a threaded interrupt handler and I don't expect much lock contention > here. > > The sysfs attribute readout would race with the interrupt handler and if it > wasn't for the firmware update support, we could very well cache all those > values. Except, the firmware update can change them all. Worse, if the > interrupt were to fire during an update, it could break that update, and I > want to prevent that from happening. Usually we simply disable interrupts from the device when updating firmware. Thanks. -- Dmitry