From patchwork Wed Sep 28 14:48:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Zaidman X-Patchwork-Id: 610386 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8D66C32771 for ; Wed, 28 Sep 2022 14:49:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234179AbiI1Ots (ORCPT ); Wed, 28 Sep 2022 10:49:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234053AbiI1Otl (ORCPT ); Wed, 28 Sep 2022 10:49:41 -0400 Received: from mail-wm1-x32b.google.com (mail-wm1-x32b.google.com [IPv6:2a00:1450:4864:20::32b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51B23B87C; Wed, 28 Sep 2022 07:49:35 -0700 (PDT) Received: by mail-wm1-x32b.google.com with SMTP id n40-20020a05600c3ba800b003b49aefc35fso1144080wms.5; Wed, 28 Sep 2022 07:49:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date; bh=6RVS2yHMtMgbWKW8mt4Gmc48qyDC1ei7uda2cYYmRkQ=; b=PDz0FEtOhXdgSMyri2zGSlMGSyFeyaZW4SIMQOA7PTFZd+wqyaeGTnCaYsPPS0MpT2 p1QoiuSRv4WLx9IFrtHTV0UwmJuMCsoaOz4rBSB3bFBKsU3ZZ7XtEbt6LUW8mMZvSG4T OSf2JzCPc9e/r3X/sfDbxZsN7BhbyU2dD7USntkdWajX99mOrPdlh09lm73aCt+FkIxc MnTlc57BneX5GYh7KMaK9bJKI4O5a9N6XrHbGkBYEYNxD0LDmMT0k1lALPkbNISrCn4C u8MKq93Mz1xquEhawmTo+4ZZ8nCdUJYdPfNI9Fb53ah1e1h6YUwWWBGo/SYJh5Juwsps D/aQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date; bh=6RVS2yHMtMgbWKW8mt4Gmc48qyDC1ei7uda2cYYmRkQ=; b=bR0RqVIasdc1tNZAyLp1oT3UES01yUrTVRN8tvaYiSDbrSgEuqLyjnqnjiqQtI587l BIIGaqyV42Ti6xcXPMjjtN0pzQ7z8hLN7u+gDRIZEiqrwvvzOhTe0e6pXys9smi32glQ +BEUTTZGHPACMP4zNAkE8bbyi0XFmJ7QL932KyxtQaB/V0mqUAY2SG1eLby15Fcs/JK7 vtZknR0M62nWBObW3adsq7jRIJFp2bIPIIRmnteoC4P+pDxLHVE3zomaGzMz/wKK3O+I hPpTIG7Kk2I8LVAMqXTClB5Ja1m5ugy9WlMGHkt26xcJZmwY2cFeotHOlvkYkExY91hP lH3w== X-Gm-Message-State: ACrzQf2TiYCTYdbac6z8fag0Si7EmtwiQWhkY3TMH5+12EKxFowP0Knl 298WMuQlGj+9zH29wgkybMsKQA1/KDCduA== X-Google-Smtp-Source: AMsMyM44eCqL1qe6yyGHm87Hu6r5TQJEWRvB1WoJdz75i9f4lHgZL6nGWlLZRI4wGyWWIDjmKvDAQA== X-Received: by 2002:a05:600c:1589:b0:3b4:fe4a:c225 with SMTP id r9-20020a05600c158900b003b4fe4ac225mr7448623wmf.150.1664376573130; Wed, 28 Sep 2022 07:49:33 -0700 (PDT) Received: from michael-VirtualBox.xsight.ent (89-139-44-91.bb.netvision.net.il. [89.139.44.91]) by smtp.googlemail.com with ESMTPSA id m35-20020a05600c3b2300b003b47b913901sm6977446wms.1.2022.09.28.07.49.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Sep 2022 07:49:32 -0700 (PDT) From: Michael Zaidman To: jikos@kernel.org Cc: linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, Michael Zaidman , Guillaume Champagne Subject: [PATCH v2 2/7] HID: ft260: improve i2c write performance Date: Wed, 28 Sep 2022 17:48:49 +0300 Message-Id: <20220928144854.5580-3-michael.zaidman@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220928144854.5580-1-michael.zaidman@gmail.com> References: <20220928144854.5580-1-michael.zaidman@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org The patch improves i2c writing performance by about 30 percent by revising the sleep time in the ft260_hid_output_report_check_status() in the following ways: 1. Reduce the sleep time and start to poll earlier: Before: $ sudo ./i2cperf -f 2 -o 2 -s 32 -r 0-0xff 13 0x51 -S Fill block with increment via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 40510 80 256 8 32 After: $ sudo ./i2cperf -f 2 -o 2 -s 32 -r 0-0xff 13 0x51 -S Fill block with increment via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 52584 80 256 8 32 2. Do not sleep when the calculated sleep time is below 2 ms: Before: $ sudo ./i2cperf -f 2 -o 2 -s 16 -r 0-0xff 13 0x51 -S Fill block with increment via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 26707 73 256 16 16 After: $ sudo ./i2cperf -f 2 -o 2 -s 16 -r 0-0xff 13 0x51 -S Fill block with increment via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 37034 73 256 16 16 Link to the i2cperf - https://github.com/MichaelZaidman/i2cperf Signed-off-by: Michael Zaidman Tested-by: Guillaume Champagne --- drivers/hid/hid-ft260.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index a35201d68b15..44106cadd746 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -345,7 +345,7 @@ static int ft260_hid_output_report(struct hid_device *hdev, u8 *data, static int ft260_hid_output_report_check_status(struct ft260_device *dev, u8 *data, int len) { - int ret, usec, try = 3; + int ret, usec, try = 100; struct hid_device *hdev = dev->hdev; ret = ft260_hid_output_report(hdev, data, len); @@ -356,10 +356,14 @@ static int ft260_hid_output_report_check_status(struct ft260_device *dev, return ret; } - /* transfer time = 1 / clock(KHz) * 10 bits * bytes */ - usec = 10000 / dev->clock * len; - usleep_range(usec, usec + 100); - ft260_dbg("wait %d usec, len %d\n", usec, len); + /* transfer time = 1 / clock(KHz) * 9 bits * bytes */ + usec = len * 9000 / dev->clock; + if (usec > 2000) { + usec -= 1500; + usleep_range(usec, usec + 100); + ft260_dbg("wait %d usec, len %d\n", usec, len); + } + do { ret = ft260_xfer_status(dev); if (ret != -EAGAIN)