From patchwork Sat Nov 5 21:11:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Zaidman X-Patchwork-Id: 13033243 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 E40B6C433FE for ; Sat, 5 Nov 2022 21:12:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229964AbiKEVMg (ORCPT ); Sat, 5 Nov 2022 17:12:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229551AbiKEVMf (ORCPT ); Sat, 5 Nov 2022 17:12:35 -0400 Received: from mail-ej1-x634.google.com (mail-ej1-x634.google.com [IPv6:2a00:1450:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A0AB611810; Sat, 5 Nov 2022 14:12:34 -0700 (PDT) Received: by mail-ej1-x634.google.com with SMTP id ud5so21380187ejc.4; Sat, 05 Nov 2022 14:12:34 -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=ZSJlpADL6FxqQLVTkCQJu3ikcoUIWPyVlc8ef31tV88=; b=KkxYKwLguylCO+MOb3Wo7CY9rR2ZX6ti/BveSUiotix/fU5ITz9DR6TU/JEBJnD8dO Emvu1hSojxp2l3AlfTrBbDxTL/kkDr3jYrO6bCLL7ud00sIAYRPnmvphyYnLUeU6p0uA 9gbBBObTNmua0uFrEeyFdPucSAf1xblJvPAy8/3vEgCfg9nonqgIET0X3SxF/xkOJzrC y2x5h+/k+6Yuq7lo/wuM2RBvIyYB6H7zRr9Xtni523bgRVNQoBLAHgfgH1CukRONGWMt YzDH4jshP0fDR3RyRYeQUIfLQn8uYJJ9LxivcyhrSszpvjdXVc+JQZKU00VX7brfOuF1 comw== 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=ZSJlpADL6FxqQLVTkCQJu3ikcoUIWPyVlc8ef31tV88=; b=2SBpT9XP5iHsE0c55dj4YP6+/pHMMI3uuMEC0odQ5zfogQwNLYZyaSrUsszL1iiET+ 73or/IDl6fegqySBjR7NV6ZLzfia858LdDOWwavstzN0GpA+bwYTqrwERrzklLANrNRR nGDnCaR3ZPGsFtoZHFNfhVn/bl1iIBU47XtGAHey64hRUwLSV49puYggiOjPB7mnGftV woiOnXRbPQ71ItWTmTolirABsR5cKyMxwZcDjiImndMva3Q/jqJ/DFj1VaM7P2gGhPwg 5y0N6w8oClCIPzb2dVwqi3/sP6VuWgtyuqzhsy1wiIKVxSUq7gAnzdwlm6wiThPuZhIW jDGg== X-Gm-Message-State: ACrzQf1QH79n6IUv16bY2Miaqr/HItWKay/vqp2/hF4oChgmYzGgWfJX CwfrNn2liiygS1WMA3qHxgo= X-Google-Smtp-Source: AMsMyM5nuu0DYzHoEpqFUn/wyXveSAK3LL1IxYlC5a6zOxMHAIx7TCnalFV2T0emNlo/rhxIvzzKsw== X-Received: by 2002:a17:907:72c3:b0:792:56d7:285a with SMTP id du3-20020a17090772c300b0079256d7285amr39988211ejc.597.1667682753198; Sat, 05 Nov 2022 14:12:33 -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.123.2022.11.05.14.12.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 05 Nov 2022 14:12:32 -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 , Guillaume Champagne Subject: [PATCH v4 01/13] HID: ft260: ft260_xfer_status routine cleanup Date: Sat, 5 Nov 2022 23:11:39 +0200 Message-Id: <20221105211151.7094-2-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 After clarifying with FTDI's support, it turned out that the error condition (bit 1) in byte 1 of the i2c status HID report is a status bit reflecting all error conditions. When bits 2, 3, or 4 are raised to 1, bit 1 is set to 1 also. Since the ft260_xfer_status routine tests the error condition bit and exits in the case of an error, the program flow never reaches the conditional expressions for 2, 3, and 4 bits when any of them indicates an error state. Though these expressions are never evaluated to true, they are checked several times per IO, increasing the ft260_xfer_status polling cycle duration. The patch removes the conditional expressions for 2, 3, and 4 bits in byte 1 of the i2c status HID report. Signed-off-by: Michael Zaidman Tested-by: Guillaume Champagne --- drivers/hid/hid-ft260.c | 30 ++++++++++-------------------- 1 file changed, 10 insertions(+), 20 deletions(-) diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index 79505c64dbfe..a35201d68b15 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -313,27 +313,17 @@ static int ft260_xfer_status(struct ft260_device *dev) if (report.bus_status & FT260_I2C_STATUS_CTRL_BUSY) return -EAGAIN; - if (report.bus_status & FT260_I2C_STATUS_BUS_BUSY) - return -EBUSY; - - if (report.bus_status & FT260_I2C_STATUS_ERROR) + /* + * The error condition (bit 1) is a status bit reflecting any + * error conditions. When any of the bits 2, 3, or 4 are raised + * to 1, bit 1 is also set to 1. + */ + if (report.bus_status & FT260_I2C_STATUS_ERROR) { + hid_err(hdev, "i2c bus error: %#02x\n", report.bus_status); return -EIO; + } - ret = -EIO; - - if (report.bus_status & FT260_I2C_STATUS_ADDR_NO_ACK) - ft260_dbg("unacknowledged address\n"); - - if (report.bus_status & FT260_I2C_STATUS_DATA_NO_ACK) - ft260_dbg("unacknowledged data\n"); - - if (report.bus_status & FT260_I2C_STATUS_ARBITR_LOST) - ft260_dbg("arbitration loss\n"); - - if (report.bus_status & FT260_I2C_STATUS_CTRL_IDLE) - ret = 0; - - return ret; + return 0; } static int ft260_hid_output_report(struct hid_device *hdev, u8 *data, @@ -376,7 +366,7 @@ static int ft260_hid_output_report_check_status(struct ft260_device *dev, break; } while (--try); - if (ret == 0 || ret == -EBUSY) + if (ret == 0) return 0; ft260_i2c_reset(hdev);