From patchwork Sat Nov 5 21:11:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Zaidman X-Patchwork-Id: 13033247 X-Patchwork-Delegate: jikos@jikos.cz 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 A7947C4332F for ; Sat, 5 Nov 2022 21:13:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230086AbiKEVNN (ORCPT ); Sat, 5 Nov 2022 17:13:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230018AbiKEVNE (ORCPT ); Sat, 5 Nov 2022 17:13:04 -0400 Received: from mail-ed1-x52f.google.com (mail-ed1-x52f.google.com [IPv6:2a00:1450:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C52911C13; Sat, 5 Nov 2022 14:12:55 -0700 (PDT) Received: by mail-ed1-x52f.google.com with SMTP id v27so12272374eda.1; Sat, 05 Nov 2022 14:12:55 -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 :message-id:reply-to; bh=YSSvluQm3NGC5J6X42oGu/YUSo51/OoBhNLx5zGbzEw=; b=bBbmixxXZOY2xxelIgiyCOhcCDIZ52+f+3hq86RrpIDyUQnjg+eM+KJnq2/o9pCGZL VbU38fSx7CUQus6utx273xANyUL68yHm7zkRFQYBs9xQKOJWhESCIGlqCu/c1jesV1Ti 2B5wBiCMJDxlZyRpkZ7RSX2+9/4UDq3GxvyK/rMC64Us86MrLKcUATGkxdDy9L2E0boZ vDLMSq2e9pCU6FrLylW3Y//4sfBmop/6DzNNIXFfqkHELrACSDXmk/W3d6DeYeD81FCV t+DysS04PJplx12tKBGVgDUDU8/ykwYV1B0kDa5QYbFgBOjV+9tZz3i+T543KUT7PLJq /sLQ== 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:message-id:reply-to; bh=YSSvluQm3NGC5J6X42oGu/YUSo51/OoBhNLx5zGbzEw=; b=8KtVdhlrUuY6+dz0hjvJuG6aI9zugvi2KtJHYzZveRyWVLl1a0DMnHYezwlrTrz0UQ +wXHxM2Y2XuAyRzLPUD99DF2Zjk/CYYblSSNS9/t0dKqdbBhq5Tz3vinyosrLgwxcNV5 3+n+z/38GugtSx90PuSkK0jxMfI3b3KfU2g0Bu4s4gwL1BOCjkpp9eM+1dpJItHqtCff Tkn93CycycsiVScwxXbrzfhsnXSeBEBHO7KjsDduX0Bv4BRTUHwYe67o2d2z/uFubzoZ iGyIBPVc624uD2ZFXk6d5T08dCEJFVxPb3lxbByNZ/N2y/iylo4V85Rx/ICkw5LujJKo PkOQ== X-Gm-Message-State: ACrzQf23UZiM9Y8ecZN5nXBkMyvdaA9Y68ZPwQsaVRHpXco9RN6nWEYo xZfdruJ4J4tkwnQxjfbMKjs= X-Google-Smtp-Source: AMsMyM5vVypAaj3/q1whPPfHQnfPsa5f8ysab+6nwFUKbs9QM+VPJPNtgQrUr+DqzWM4PRlZLV/ewA== X-Received: by 2002:a05:6402:5250:b0:461:e870:850f with SMTP id t16-20020a056402525000b00461e870850fmr41969402edd.404.1667682774203; Sat, 05 Nov 2022 14:12:54 -0700 (PDT) Received: from michael-VirtualBox.. (89-138-220-136.bb.netvision.net.il. [89.138.220.136]) by smtp.googlemail.com with ESMTPSA id ta19-20020a1709078c1300b0073d796a1043sm1323502ejc.123.2022.11.05.14.12.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 05 Nov 2022 14:12:53 -0700 (PDT) From: Michael Zaidman To: jikos@kernel.org Cc: linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, linux-i2c@vger.kernel.org, Enrik.Berkhan@inka.de, Michael Zaidman Subject: [PATCH v4 05/13] HID: ft260: improve i2c large reads performance Date: Sat, 5 Nov 2022 23:11:43 +0200 Message-Id: <20221105211151.7094-6-michael.zaidman@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221105211151.7094-1-michael.zaidman@gmail.com> References: <20221105211151.7094-1-michael.zaidman@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org The patch increases the read buffer size to 180 bytes. It reduces the number of ft260_i2c_read() calls by three, improving the big reads performance. $ sudo i2ctransfer -y -f 13 w2@0x51 0x0 0x0 r180 Before: [ +4.071878] ft260_i2c_write_read: off 0x0 rlen 180 wlen 2 [ +0.000005] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0 [ +0.001097] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000175] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000004] ft260_i2c_read: rep 0xc2 addr 0x51 len 180 rlen 60 flag 0x3 [ +0.008579] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000208] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 120 rlen 60 flag 0x0 [ +0.008794] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000181] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000002] ft260_i2c_read: rep 0xc2 addr 0x51 len 60 rlen 60 flag 0x4 [ +0.008817] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000223] ft260_xfer_status: bus_status 0x20, clock 100 After: [ +11.611642] ft260_i2c_write_read: off 0x0 rlen 180 wlen 2 [ +0.000005] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0 [ +0.008001] ft260_xfer_status: bus_status 0x20, clock 100 [ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 180 rlen 180 flag 0x7 [ +0.008994] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.007987] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.007992] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000206] ft260_xfer_status: bus_status 0x20, clock 100 Suggested-by: Enrik Berkhan Signed-off-by: Michael Zaidman --- drivers/hid/hid-ft260.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index a354089bb747..91f9087e49dc 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -30,12 +30,19 @@ MODULE_PARM_DESC(debug, "Toggle FT260 debugging messages"); #define FT260_REPORT_MAX_LENGTH (64) #define FT260_I2C_DATA_REPORT_ID(len) (FT260_I2C_REPORT_MIN + (len - 1) / 4) + /* - * The input report format assigns 62 bytes for the data payload, but ft260 - * returns 60 and 2 in two separate transactions. To minimize transfer time - * in reading chunks mode, set the maximum read payload length to 60 bytes. - */ -#define FT260_RD_DATA_MAX (60) + * The ft260 input report format defines 62 bytes for the data payload, but + * when requested 62 bytes, the controller returns 60 and 2 in separate input + * reports. To achieve better performance with the multi-report read data + * transfers, we set the maximum read payload length to a multiple of 60. + * With a 100 kHz I2C clock, one 240 bytes read takes about 1/27 second, + * which is excessive; On the other hand, some higher layer drivers like at24 + * or optoe limit the i2c reads to 128 bytes. To not block other drivers out + * of I2C for potentially troublesome amounts of time, we select the maximum + * read payload length to be 180 bytes. +*/ +#define FT260_RD_DATA_MAX (180) #define FT260_WR_DATA_MAX (60) /*