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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4DC6C433F5 for ; Wed, 10 Nov 2021 06:27:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD18E61168 for ; Wed, 10 Nov 2021 06:27:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229772AbhKJGao (ORCPT ); Wed, 10 Nov 2021 01:30:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45160 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229731AbhKJGao (ORCPT ); Wed, 10 Nov 2021 01:30:44 -0500 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F65BC061764 for ; Tue, 9 Nov 2021 22:27:57 -0800 (PST) Received: by mail-pj1-x102c.google.com with SMTP id n15-20020a17090a160f00b001a75089daa3so970096pja.1 for ; Tue, 09 Nov 2021 22:27:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=e8+NRAWHR3bT/UkfHvfLg3cyGBdlKVJIKDCcEWXJStk=; b=Kcwa+Rwv5TUsHcA34B/FdYgUS+MrNBmt0cgNenYYOVvvewoDFdE5FQodbHxYG7CEsK jW9RrLVzTrGTXuVeWoSTZukAD8FRscGlb46157pMJ7hYngnuZWxxp8j+tXcNGnuEMsL3 O8sRbTldCUvW7MgPqdTdpHlagnUtDIkiiPiERrL7BVlP8De4qEDZy8Gzp5yoLa0wUBPP rC06HVvQCYMTSDYJkMzR7fAgj1VSniGdJYhvZyA17YV4CcMKJQxYbUqmBhQXCOT8HbxE VIN0usBM9JJGvzEWNeBgHpAfD8DP/OMhaOZKdZFwMWtwo4rtSoMbkW+Yc/RO8NHIvaSv GOxA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=e8+NRAWHR3bT/UkfHvfLg3cyGBdlKVJIKDCcEWXJStk=; b=WTUy0iUya6qsx+lSIzZ/0s/lfutoHE1ev/yDRKEXm4o8wyq0wr8uUweqYhFUidu1e8 Qkbyt/zD7NskCrT4CiZo/jJ+Mvcq2vSexsUSrDwqV/wyEMC2r//zK+tRoXajRrCu7mY+ jBRFiym+27ijawyj4AcCsJR5Prsj7AuRYMgoZrfTKuLUnGyiJkUnYGBot9gNRCDhxYX3 YwMXkQ3lLKg7RYDCl7KOaSDEd80jHZWzixzK3OhKivZc+YPxDYgG6urDA6SWWhHW8fO+ 48ycIS+1K12Mn1WaPgzFcN4Zyy7uCQjwfffDPFOn04jgx47z4JN+LwA8aHufRV38nP3t ZV8w== X-Gm-Message-State: AOAM530/ICM4TYq27LGzp5MlcNxhJv5vPSxxLgFuSMKORq8znbSSMwZO AKP0dzEnJMwWC9cR3dZi2yE= X-Google-Smtp-Source: ABdhPJwBOc0gWhrcPJ4wdOSQszdw5RRVgD0MU1s/MISABcsxkiGCkiBLbOGlSz3061NIlvHURfGEVQ== X-Received: by 2002:a17:90b:e83:: with SMTP id fv3mr14294912pjb.115.1636525677016; Tue, 09 Nov 2021 22:27:57 -0800 (PST) Received: from google.com ([2620:15c:202:201:b345:ee3a:151d:b1d1]) by smtp.gmail.com with ESMTPSA id c21sm23682471pfl.15.2021.11.09.22.27.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Nov 2021 22:27:55 -0800 (PST) Date: Tue, 9 Nov 2021 22:27:53 -0800 From: Dmitry Torokhov To: Marek Vasut Cc: linux-input@vger.kernel.org, Joe Hung , Luca Hsu Subject: Re: [PATCH] Input: ili210x - Improve polled sample spacing Message-ID: References: <20211108005216.480525-1-marex@denx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org On Mon, Nov 08, 2021 at 12:04:30PM +0100, Marek Vasut wrote: > On 11/8/21 4:37 AM, Dmitry Torokhov wrote: > > Hi Marek, > > Hi, > > [...] > > > > diff --git a/drivers/input/touchscreen/ili210x.c b/drivers/input/touchscreen/ili210x.c > > > index a3b71a9511eb3..b2d9fe1e1c707 100644 > > > --- a/drivers/input/touchscreen/ili210x.c > > > +++ b/drivers/input/touchscreen/ili210x.c > > > @@ -328,10 +328,13 @@ static irqreturn_t ili210x_irq(int irq, void *irq_data) > > > const struct ili2xxx_chip *chip = priv->chip; > > > u8 touchdata[ILI210X_DATA_SIZE] = { 0 }; > > > bool keep_polling; > > > + ktime_t time_next; > > > + s64 time_delta; > > > bool touch; > > > int error; > > > do { > > > + time_next = ktime_add_ms(ktime_get(), ILI2XXX_POLL_PERIOD); > > > error = chip->get_touch_data(client, touchdata); > > > if (error) { > > > dev_err(&client->dev, > > > @@ -341,8 +344,11 @@ static irqreturn_t ili210x_irq(int irq, void *irq_data) > > > touch = ili210x_report_events(priv, touchdata); > > > keep_polling = chip->continue_polling(touchdata, touch); > > > - if (keep_polling) > > > - msleep(ILI2XXX_POLL_PERIOD); > > > + if (keep_polling) { > > > + time_delta = ktime_us_delta(time_next, ktime_get()); > > > > Do we really need to use exact time, or ktime_get_coarse() is good > > enough, as it is cheaper? > > ktime_get_coarse() introduces multi-millisecond jitter into the samples if > you have low HZ setting, which isn't really nice. That's also why I use > ktime and not jiffies here, jiffies has the same problem. Applied, thank you. -- Dmitry