From patchwork Mon Jun 19 10:27:39 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: 9795731 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 0504D6020B for ; Mon, 19 Jun 2017 10:27:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CA1C526E97 for ; Mon, 19 Jun 2017 10:27:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BED4D27A98; Mon, 19 Jun 2017 10:27:48 +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 34B3526E97 for ; Mon, 19 Jun 2017 10:27:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753796AbdFSK1r (ORCPT ); Mon, 19 Jun 2017 06:27:47 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:40303 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753682AbdFSK1r (ORCPT ); Mon, 19 Jun 2017 06:27:47 -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 1dMtuJ-0002Z6-HG; Mon, 19 Jun 2017 10:27:44 +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 v3] platform/x86: dell-laptop: Fix bogus keyboard backlight sysfs interface Date: Mon, 19 Jun 2017 18:27:39 +0800 Message-Id: <20170619102739.30449-1-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 both ON and OFF token should be present to support keyboard backlight. 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 --- 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; }