From patchwork Thu May 11 18:52:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Torokhov X-Patchwork-Id: 681039 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 3CF60C7EE22 for ; Thu, 11 May 2023 18:53:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238927AbjEKSxO (ORCPT ); Thu, 11 May 2023 14:53:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57588 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238932AbjEKSxL (ORCPT ); Thu, 11 May 2023 14:53:11 -0400 Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E281C49FA; Thu, 11 May 2023 11:53:07 -0700 (PDT) Received: by mail-pl1-x62d.google.com with SMTP id d9443c01a7336-1aad5245632so64988175ad.3; Thu, 11 May 2023 11:53:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1683831187; x=1686423187; 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=b3FHdxcnZDHBJfwaP/5YmMMNOS9nBKD4If1FaL3R/o8=; b=ec49sEyTE5xx2tkdVvEwvcakKrHRzVcHLnXJA2iPrdp29iMdhPkl+peowh9GGhMeby RyzV24uF5jeUp7LYejufSY9mWDxWI0GHjGcZDvBVbRCcue5ofVy+wLNq1UX13CWUbgj6 xycCENFG8MLMeQ3KvsZa1MTXqJ4aVnME/GvxhYpDGf0WH/ewu4zOzL+tJ27cpRX4KUCW Hs11e0UtOZLlNdbAEJnCWSG9dLqCpbfmtInVdZ5SzKnnIpuolJQo6YtOV3vjp3E+qtVP Dv0iKOx1atQtPn4E2Gz0tb5GB4u4eS4Wda3TZIOCXUJiUpxgNPO5zXlCVDeQcJWLGInE P5Hg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683831187; x=1686423187; 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=b3FHdxcnZDHBJfwaP/5YmMMNOS9nBKD4If1FaL3R/o8=; b=NEHLjq5L9RAhqBV9GBgK3vnawOkRWkI5jfyn2fCaU3CLnIDnUL2HOVF5G9WKuHmlWx klleMQXLycEJu4thQ0LTh7dw/wYxObLAgi6Ws9YHE6nHICOIzGyHXYU+k/RRcSdgUnX2 31Ax8hixl6fLb/sXA0qAa8EpKhMX2crRvptOV8NP3S+Q5e4LOKE8qbxFSOJD05QkG2Oe BcZ40ZRiPSSQ/dLpflPvblVszY8jm8MB7VBXBm6iqM4HSiDhhaHZnN0VglHy2oW0Cmjt umlO8yLlFcZt1/varPiIr/RQgTaz/LXrvPbL0IrEoTxpqrFk2P0zln2A+f/5sD2+4vwR Vezg== X-Gm-Message-State: AC+VfDw8kqF2AzuJCKpAdG8BjAkgU/0LhCXtcGPLvtUoxetn+fsOzKpP wjMYNyY1Tf7+A5tvd8wz6pQjucPxbz4= X-Google-Smtp-Source: ACHHUZ5PFqhArb3xXxeEE0naJWLQMFeiWuCjw2lAkk4uUP+2VZdnKQwzTZbSviNJEokbv5vbMHBrqQ== X-Received: by 2002:a17:903:44c:b0:1ab:27e7:ad76 with SMTP id iw12-20020a170903044c00b001ab27e7ad76mr21361943plb.45.1683831186628; Thu, 11 May 2023 11:53:06 -0700 (PDT) Received: from dtor-ws.mtv.corp.google.com ([2620:15c:9d:2:84a:ed9c:4024:c347]) by smtp.gmail.com with ESMTPSA id q5-20020a170902788500b001a980a23804sm6288995pll.4.2023.05.11.11.53.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 May 2023 11:53:06 -0700 (PDT) From: Dmitry Torokhov To: linux-input@vger.kernel.org Cc: Raul E Rangel , linux-kernel@vger.kernel.org Subject: [PATCH 7/7] Input: libps2 - do not discard non-ack bytes when controlling LEDs Date: Thu, 11 May 2023 11:52:47 -0700 Message-ID: <20230511185252.386941-8-dmitry.torokhov@gmail.com> X-Mailer: git-send-email 2.40.1.606.ga4b1b128d6-goog In-Reply-To: <20230511185252.386941-1-dmitry.torokhov@gmail.com> References: <20230511185252.386941-1-dmitry.torokhov@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org Upon receiving a PS/2 command the device and controller are supposed to stop sending normal data (scancodes or movement packets) and instead immediately start delivering ACK/NAK and command response. Unfortunately often EC has an output buffer which may contain latched data by the time the EC receives a command from the host. The kernel used to ignore such data, but that may cause "stuck" keys if the data dropped happens to be a break code or a part of a break code. This occasionally happens, for example, on Chromebooks when the kernel tries to toggle CapsLock LED on a keyboard while user releases Alt+Search keyboard shortcut. Fix this by passing the first non-ACK byte to the normal handler for a handful of PS/2 commands that are expected to be used during normal device operation (as opposed to probe/configuration time). Signed-off-by: Dmitry Torokhov Reviewed-by: Raul E Rangel --- drivers/input/serio/libps2.c | 36 ++++++++++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-) diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c index 7c5fc853072a..6d78a1fe00c1 100644 --- a/drivers/input/serio/libps2.c +++ b/drivers/input/serio/libps2.c @@ -21,7 +21,10 @@ #define PS2_CMD_SETSCALE11 0x00e6 #define PS2_CMD_SETRES 0x10e8 +#define PS2_CMD_EX_SETLEDS 0x20eb +#define PS2_CMD_SETLEDS 0x10ed #define PS2_CMD_GETID 0x02f2 +#define PS2_CMD_SETREP 0x10f3 /* Set repeat rate/set report rate */ #define PS2_CMD_RESET_BAT 0x02ff #define PS2_RET_BAT 0xaa @@ -35,6 +38,7 @@ #define PS2_FLAG_CMD1 BIT(2) /* Waiting for the first byte of command response */ #define PS2_FLAG_WAITID BIT(3) /* Command executing is GET ID */ #define PS2_FLAG_NAK BIT(4) /* Last transmission was NAKed */ +#define PS2_FLAG_PASS_NOACK BIT(5) /* Pass non-ACK byte to receive handler */ static int ps2_do_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout, unsigned int max_attempts) @@ -281,9 +285,28 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command) serio_pause_rx(ps2dev->serio); - /* Some mice do not ACK the "get ID" command, prepare to handle this. */ - ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0; ps2dev->cmdcnt = receive; + + switch (command) { + case PS2_CMD_GETID: + /* + * Some mice do not ACK the "get ID" command, prepare to + * handle this. + */ + ps2dev->flags = PS2_FLAG_WAITID; + break; + + case PS2_CMD_SETLEDS: + case PS2_CMD_EX_SETLEDS: + case PS2_CMD_SETREP: + ps2dev->flags = PS2_FLAG_PASS_NOACK; + break; + + default: + ps2dev->flags = 0; + break; + } + if (receive) { /* Indicate that we expect response to the command. */ ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1; @@ -512,14 +535,19 @@ static void ps2_handle_ack(struct ps2dev *ps2dev, u8 data) * Do not signal errors if we get unexpected reply while * waiting for an ACK to the initial (first) command byte: * the device might not be quiesced yet and continue - * delivering data. + * delivering data. For certain commands (such as set leds and + * set repeat rate) that can be used during normal device + * operation, we even pass this data byte to the normal receive + * handler. * Note that we reset PS2_FLAG_WAITID flag, so the workaround * for mice not acknowledging the Get ID command only triggers * on the 1st byte; if device spews data we really want to see * a real ACK from it. */ dev_dbg(&ps2dev->serio->dev, "unexpected %#02x\n", data); - ps2dev->flags &= ~PS2_FLAG_WAITID; + if (ps2dev->flags & PS2_FLAG_PASS_NOACK) + ps2dev->receive_handler(ps2dev, data); + ps2dev->flags &= ~(PS2_FLAG_WAITID | PS2_FLAG_PASS_NOACK); return; }