From patchwork Wed May 25 07:47:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Zaidman X-Patchwork-Id: 576125 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 0A13EC433FE for ; Wed, 25 May 2022 07:48:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233895AbiEYHsv (ORCPT ); Wed, 25 May 2022 03:48:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235723AbiEYHst (ORCPT ); Wed, 25 May 2022 03:48:49 -0400 Received: from mail-ed1-x530.google.com (mail-ed1-x530.google.com [IPv6:2a00:1450:4864:20::530]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E6E087A805; Wed, 25 May 2022 00:48:46 -0700 (PDT) Received: by mail-ed1-x530.google.com with SMTP id i40so25975249eda.7; Wed, 25 May 2022 00:48:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=EPynCkzORF20XuMD0bXtGUG6EP2A5Zo3+FVMietPcZE=; b=GjqqkGiRRZblEkRH2U6xkeHVGMYUun9iTgUsZ+Pa+GD8goBEWkreCgNtYz9dDfGQxt Zd9X5kG43LsTCMslMecPruEpYViBwpM+CriKB5Rk/ArGEU2Ds/4uZoshU2LdoYWk/pgw 2u9IpeyM0HhEeLklfuoLDg/geyvr4K8jSzg/N5ORQ8y3RnQWv03DPg7IEBmLz+tymMLu rBwzzmB1m8VCqj3mcMzXkCtehD8mCf+yar4HVam9bSIprwZCAPZLHDDFMFeC6VhAPvBe mNnrQHskxxhS5VMOVbA8Ilw8n2y0CQESgIGQBsz7ISHXNb3IAMHT5Qa5PZAzu5GgDhg4 LSVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=EPynCkzORF20XuMD0bXtGUG6EP2A5Zo3+FVMietPcZE=; b=1xfKAXNr0JNiUS8Mb17jl4WUyWMbQhJRHMXi1K0WcBKRiE3hFBBqLqfhP7sF7BLu/E 06DNJXn4f0tpSMnG0/cmm57SVK5TjV/x5AM09AHOiX/PlhdbtT0ZiHZvRItzl7ebhkme UtoEhdADFs1adjL3QJHYjcp6xrU8rpIJwFPyQD8VkBlnHh703ejrpywzDLoT8FiVcJp/ xvSAtVSPhIkvCwVxppkLxlGNe1TFFyR1OBA7SY9WNgcajY0cEZMbctAnglHcFG/QCEbA clJReW4shw+j3JmdjxNwEAT3NlXFFYIc/SPAvNGmiNaGA3s3ZObP4Ou/ftGue/cFrdqV vWyg== X-Gm-Message-State: AOAM531/F64w5/2P/kq/pvVs2/rxzDd5KlzPJyQH436IYsIEApvdNjY5 FP8T1J2AKXbGrSRRU+TfgDE= X-Google-Smtp-Source: ABdhPJxGPyhSLiXKVkPe2sk+qtaGDafwnLFhLiBhQLBcT7f1HHCHojo13Uc+eZdwaWjmoAoEzHKfpg== X-Received: by 2002:a05:6402:509:b0:42a:b6c9:eac with SMTP id m9-20020a056402050900b0042ab6c90eacmr32170452edv.225.1653464925492; Wed, 25 May 2022 00:48:45 -0700 (PDT) Received: from localhost.localdomain (109-186-136-71.bb.netvision.net.il. [109.186.136.71]) by smtp.googlemail.com with ESMTPSA id v1-20020aa7d641000000b0042acd78014esm10230533edr.11.2022.05.25.00.48.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 May 2022 00:48:45 -0700 (PDT) From: Michael Zaidman To: jikos@kernel.org, benjamin.tissoires@redhat.com, wsa@kernel.org Cc: linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, linux-i2c@vger.kernel.org, champagne.guillaume.c@gmail.com, mathieu.gallichand@sonatest.com, Michael Zaidman Subject: [PATCH v1 2/5] HID: ft260: improve i2c write performance Date: Wed, 25 May 2022 10:47:54 +0300 Message-Id: <20220525074757.7519-3-michael.zaidman@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220525074757.7519-1-michael.zaidman@gmail.com> References: <20220525074757.7519-1-michael.zaidman@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@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 --- 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)