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 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8E46BEA8131 for ; Tue, 10 Feb 2026 15:50:15 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 311E810E5B4; Tue, 10 Feb 2026 15:50:15 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=tuxedocomputers.com header.i=@tuxedocomputers.com header.b="c9aPMa/w"; dkim-atps=neutral Received: from mail.tuxedocomputers.com (mail.tuxedocomputers.com [157.90.84.7]) by gabe.freedesktop.org (Postfix) with ESMTPS id 468E610E106; Mon, 9 Feb 2026 22:22:09 +0000 (UTC) Received: from [192.168.178.24] (i5C75F6C0.versanet.de [92.117.246.192]) (Authenticated sender: wse@tuxedocomputers.com) by mail.tuxedocomputers.com (Postfix) with ESMTPSA id BB0D32FC0061; Mon, 9 Feb 2026 23:22:06 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tuxedocomputers.com; s=default; t=1770675727; 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=9UQ3B7W/cx4yivTTdMfnQWuYxY1YQbuzbQqMSYQKC7U=; b=c9aPMa/w3aAfc3aoiwZ8rF93IIW3TdWbI6+rVETGE+o0bglVOJ42a65aHF0mEd+fMbjt4Q b1RkDHbfu6CZ6KsJGqX8yAqT8RR/JoS8Z+td31zsljH1Q7CVLR6Nz3YdEItTBktWgoHJ2T 89XnEhYIdsR5m7maqEi40RGEO5hlNko= Authentication-Results: mail.tuxedocomputers.com; auth=pass smtp.auth=wse@tuxedocomputers.com smtp.mailfrom=wse@tuxedocomputers.com Message-ID: Date: Mon, 9 Feb 2026 23:22:06 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] drm/i915/display: Add quirk to force backlight type on some TUXEDO devices To: "Kandpal, Suraj" , Jani Nikula , "Vivi, Rodrigo" , Joonas Lahtinen , Tvrtko Ursulin , David Airlie , Simona Vetter Cc: "intel-gfx@lists.freedesktop.org" , "intel-xe@lists.freedesktop.org" , "dri-devel@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" References: <20260121223944.1104951-1-wse@tuxedocomputers.com> Content-Language: en-US From: Werner Sembach In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Tue, 10 Feb 2026 15:50:14 +0000 X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" Hi Suraj, Am 29.01.26 um 05:23 schrieb Kandpal, Suraj: >> Subject: [PATCH v2] drm/i915/display: Add quirk to force backlight type on >> some TUXEDO devices >> >> The display backlight on TUXEDO DX1708 and InsanityBook 15 v1 with panels >> AUO 12701 and AUO 12701 must be forced to >> INTEL_DP_AUX_BACKLIGHT_ON to be able to control the brightness. >> >> This could already be archived via a module parameter, but this patch adds a >> quirk to apply this by default on the mentioned devices. >> >> This patch does not actually test for the exact panels as the id that is used in >> the intel_dpcd_quirks list is sadly zeroed on the devices, but afaik all these >> devices use try_intel_interface first anyway so all the quirk does is to add the >> fallback to try_vesa_interface, so the behaviour on the devices not needing >> the quirk and fallback should functionally stay the same. > Hi Sembach, > > Thanks for the patch. I would recommend opening a gitlab issue with all the details > (platform, edp version etc), Along with dmesg logs with drm.debug set to 0x10e and kernel > Version mentioned . So we can root cause this properly and determine is an actual quirk is required or not. > Use can use this as a guide https://drm.pages.freedesktop.org/intel-docs/how-to-file-i915-bugs.html Done: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15679 Best Regards, Werner > > Regards, > Suraj Kandpal > >> Cc: stable@vger.kernel.org >> Signed-off-by: Werner Sembach >> --- >> .../drm/i915/display/intel_dp_aux_backlight.c | 9 ++++++- >> drivers/gpu/drm/i915/display/intel_quirks.c | 25 ++++++++++++++++++- >> drivers/gpu/drm/i915/display/intel_quirks.h | 1 + >> 3 files changed, 33 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c >> b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c >> index 0a3a3f6a5f9d8..bbdfa142d084d 100644 >> --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c >> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c >> @@ -41,6 +41,7 @@ >> #include "intel_display_types.h" >> #include "intel_dp.h" >> #include "intel_dp_aux_backlight.h" >> +#include "intel_quirks.h" >> >> /* >> * DP AUX registers for Intel's proprietary HDR backlight interface. We define >> @@ -661,11 +662,17 @@ int intel_dp_aux_init_backlight_funcs(struct >> intel_connector *connector) >> struct drm_device *dev = connector->base.dev; >> struct intel_panel *panel = &connector->panel; >> bool try_intel_interface = false, try_vesa_interface = false; >> + int enable_dpcd_backlight; >> >> /* Check the VBT and user's module parameters to figure out which >> * interfaces to probe >> */ >> - switch (display->params.enable_dpcd_backlight) { >> + enable_dpcd_backlight = display->params.enable_dpcd_backlight; >> + if (enable_dpcd_backlight == INTEL_DP_AUX_BACKLIGHT_AUTO && >> + intel_has_dpcd_quirk(intel_dp, >> QUIRK_ENABLE_DPCD_BACKLIGHT)) >> + enable_dpcd_backlight = INTEL_DP_AUX_BACKLIGHT_ON; >> + >> + switch (enable_dpcd_backlight) { >> case INTEL_DP_AUX_BACKLIGHT_OFF: >> return -ENODEV; >> case INTEL_DP_AUX_BACKLIGHT_AUTO: >> diff --git a/drivers/gpu/drm/i915/display/intel_quirks.c >> b/drivers/gpu/drm/i915/display/intel_quirks.c >> index d2e16b79d6be1..df20930f73f75 100644 >> --- a/drivers/gpu/drm/i915/display/intel_quirks.c >> +++ b/drivers/gpu/drm/i915/display/intel_quirks.c >> @@ -86,6 +86,14 @@ static void quirk_edp_limit_rate_hbr2(struct >> intel_display *display) >> drm_info(display->drm, "Applying eDP Limit rate to HBR2 quirk\n"); } >> >> +static void quirk_enable_dpcd_backlight(struct intel_dp *intel_dp) { >> + struct intel_display *display = to_intel_display(intel_dp); >> + >> + intel_set_dpcd_quirk(intel_dp, QUIRK_ENABLE_DPCD_BACKLIGHT); >> + drm_info(display->drm, "Applying Enable DPCD Backlight quirk\n"); } >> + >> struct intel_quirk { >> int device; >> int subsystem_vendor; >> @@ -251,7 +259,22 @@ static const struct intel_dpcd_quirk >> intel_dpcd_quirks[] = { >> .sink_oui = SINK_OUI(0x38, 0xec, 0x11), >> .hook = quirk_fw_sync_len, >> }, >> - >> + /* TUXEDO InsanityBook 15 v1 */ >> + { >> + .device = 0x591b, >> + .subsystem_vendor = 0x1558, >> + .subsystem_device = 0x9501, >> + .sink_oui = SINK_OUI(0x38, 0xec, 0x11), >> + .hook = quirk_enable_dpcd_backlight, >> + }, >> + /* TUXEDO DX1708 */ >> + { >> + .device = 0x3e9b, >> + .subsystem_vendor = 0x1558, >> + .subsystem_device = 0x8500, >> + .sink_oui = SINK_OUI(0x38, 0xec, 0x11), >> + .hook = quirk_enable_dpcd_backlight, >> + }, >> }; >> >> void intel_init_quirks(struct intel_display *display) diff --git >> a/drivers/gpu/drm/i915/display/intel_quirks.h >> b/drivers/gpu/drm/i915/display/intel_quirks.h >> index 06da0e286c67c..686f306ab4472 100644 >> --- a/drivers/gpu/drm/i915/display/intel_quirks.h >> +++ b/drivers/gpu/drm/i915/display/intel_quirks.h >> @@ -21,6 +21,7 @@ enum intel_quirk_id { >> QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK, >> QUIRK_FW_SYNC_LEN, >> QUIRK_EDP_LIMIT_RATE_HBR2, >> + QUIRK_ENABLE_DPCD_BACKLIGHT, >> }; >> >> void intel_init_quirks(struct intel_display *display); >> -- >> 2.43.0