From patchwork Tue Jun 20 03:05:19 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Kai-Heng Feng X-Patchwork-Id: 9798431 X-Patchwork-Delegate: andy.shevchenko@gmail.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B30F5600C5 for ; Tue, 20 Jun 2017 03:05:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A17F51FFDB for ; Tue, 20 Jun 2017 03:05:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 95FFF27F93; Tue, 20 Jun 2017 03:05:36 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E153927A98 for ; Tue, 20 Jun 2017 03:05:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750925AbdFTDFd (ORCPT ); Mon, 19 Jun 2017 23:05:33 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:48374 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750863AbdFTDFb (ORCPT ); Mon, 19 Jun 2017 23:05:31 -0400 Received: from [175.41.48.77] (helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1dN9Tr-0002V4-OC; Tue, 20 Jun 2017 03:05:28 +0000 From: Kai-Heng Feng To: pali.rohar@gmail.com Cc: andy@infradead.org, mjg59@srcf.ucam.org, dvhart@infradead.org, platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, Kai-Heng Feng Subject: [PATCH v4] platform/x86: dell-laptop: Fix bogus keyboard backlight sysfs interface Date: Tue, 20 Jun 2017 11:05:19 +0800 Message-Id: <20170620030519.629-1-kai.heng.feng@canonical.com> X-Mailer: git-send-email 2.13.1 MIME-Version: 1.0 Sender: platform-driver-x86-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Dell Latitude 3160 does not have keyboard backlight, but there is a sysfs interface for it, which does nothing at all. KBD_LED_ON_TOKEN is the only token can be found. Since it doesn't have KBD_LED_OFF_TOKEN or KBD_LED_AUTO_*_TOKEN, it should be safe to assume at least two tokens should be present to support keyboard backlight. Not all models have ON token - they may have multiple AUTO tokens instead. Models which do not use SMBIOS token to control keyboard backlight, also have this issue. Brightness level is 0 on these models. Verified on Dell Inspiron 3565. Reports keyboard backlight is supported only when at least two modes are present. Signed-off-by: Kai-Heng Feng Reviewed-by: Pali Rohár --- v4: Change commit log - not all models have ON token. v3: Change the logic, there should be at least two modes present to claim it supports backlight. Suggested by Pali Rohár. v2: The only token can be found is actually KBD_LED_ON_TOKEN, which is BIT(5), instead of KBD_LED_OFF_TOKEN. Change commit log accordingly. Use token bit to make the intention more clear. Also consider kbd_mode_levels_count and kbd_info.levels, suggested by Pali Rohár. Use XOR to simplify the bitmask comparison, suggested by Andy Shevchenko. drivers/platform/x86/dell-laptop.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c index ec202094bd50..f42159fd2031 100644 --- a/drivers/platform/x86/dell-laptop.c +++ b/drivers/platform/x86/dell-laptop.c @@ -1510,7 +1510,11 @@ static void kbd_init(void) ret = kbd_init_info(); kbd_init_tokens(); - if (kbd_token_bits != 0 || ret == 0) + /* + * Only supports keyboard backlight when it has at least two modes. + */ + if ((ret == 0 && (kbd_info.levels != 0 || kbd_mode_levels_count >= 2)) + || kbd_get_valid_token_counts() >= 2) kbd_led_present = true; }