From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2349BC2D0C0 for ; Mon, 23 Dec 2019 07:20:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E7466206B7 for ; Mon, 23 Dec 2019 07:20:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="BKvS60xx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726027AbfLWHUu (ORCPT ); Mon, 23 Dec 2019 02:20:50 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:36756 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725855AbfLWHUt (ORCPT ); Mon, 23 Dec 2019 02:20:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1577085648; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=MW6YhL+RcyQYvYpj5YrVwXN8MDvDRWOnMuiAt/nHw6w=; b=BKvS60xxrDyGPxcHtlBgjcjNqD9a/6K/bFjDzZxTegfUrLvKN4Tvx8Mn1KYdyDiNMts4+c apJnNY9wDigX95BU6Kwoe/V9wYH0g7rOw2TeO9h4/0JJB+XqADkXVZxR7gL0+5ec02hGEq R1lLAfOA1TsXVXv3x+cQL9YVRUZ3PY8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-336-KC-JDB_cOcm-mTCqJAK6MA-1; Mon, 23 Dec 2019 02:20:45 -0500 X-MC-Unique: KC-JDB_cOcm-mTCqJAK6MA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 63424800D48; Mon, 23 Dec 2019 07:20:44 +0000 (UTC) Received: from localhost.localdomain (ovpn-12-202.pek2.redhat.com [10.72.12.202]) by smtp.corp.redhat.com (Postfix) with ESMTP id CD95A808F5; Mon, 23 Dec 2019 07:20:38 +0000 (UTC) Subject: Re: [4/5] drm/i915: Auto detect DPCD backlight support by default To: Lyude Paul , intel-gfx@lists.freedesktop.org Cc: David Airlie , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org References: <20191122231616.2574-5-lyude@redhat.com> From: Perr Yuan Message-ID: <3ba84125-ab4c-e1a7-cb74-b65638f1c2d5@redhat.com> Date: Mon, 23 Dec 2019 02:20:36 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.0 MIME-Version: 1.0 In-Reply-To: <20191122231616.2574-5-lyude@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/22/19 6:16 PM, Lyude Paul wrote: > Turns out we actually already have some companies, such as Lenovo, > shipping machines with AMOLED screens that don't allow controlling the > backlight through the usual PWM interface and only allow controlling it > through the standard EDP DPCD interface. One example of one of these > laptops is the X1 Extreme 2nd Generation. > > Since we've got systems that need this turned on by default now to have > backlight controls working out of the box, let's start auto-detecting it > for systems by default based on what the VBT tells us. We do this by > changing the default value for the enable_dpcd_backlight module param > from 0 to -1. > > Signed-off-by: Lyude Paul > Reviewed-by: Jani Nikula > --- > drivers/gpu/drm/i915/i915_params.c | 2 +- > drivers/gpu/drm/i915/i915_params.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c > index 1dd1f3652795..31eed60c167e 100644 > --- a/drivers/gpu/drm/i915/i915_params.c > +++ b/drivers/gpu/drm/i915/i915_params.c > @@ -172,7 +172,7 @@ i915_param_named_unsafe(inject_probe_failure, uint, 0400, > > i915_param_named(enable_dpcd_backlight, int, 0600, > "Enable support for DPCD backlight control" > - "(-1=use per-VBT LFP backlight type setting, 0=disabled [default], 1=enabled)"); > + "(-1=use per-VBT LFP backlight type setting [default], 0=disabled, 1=enabled)"); > > #if IS_ENABLED(CONFIG_DRM_I915_GVT) > i915_param_named(enable_gvt, bool, 0400, > diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h > index 31b88f297fbc..a79d0867f77a 100644 > --- a/drivers/gpu/drm/i915/i915_params.h > +++ b/drivers/gpu/drm/i915/i915_params.h > @@ -64,7 +64,7 @@ struct drm_printer; > param(int, reset, 3) \ > param(unsigned int, inject_probe_failure, 0) \ > param(int, fastboot, -1) \ > - param(int, enable_dpcd_backlight, 0) \ > + param(int, enable_dpcd_backlight, -1) \ > param(char *, force_probe, CONFIG_DRM_I915_FORCE_PROBE) \ > param(unsigned long, fake_lmem_start, 0) \ > /* leave bools at the end to not create holes */ \ > Tested-by:Perry Yuan