From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B156C43F4BC; Thu, 30 Jul 2026 14:30:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785421811; cv=none; b=asGs1KOcAnGaDczcyle4QWNZ/4jy3vHvoOT3WD0k24jD6ispb+05XVhdes/85WoK6HkG/sFBM7CRBRYu66l/C3E/XauWK9DA8nCBYqn6a4i6laBO9GAA7ROiPVvl9yJUJvWlco5dJjsaMPwhv93ATcNUCVVVX/xZoMxoVHaVAGc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785421811; c=relaxed/simple; bh=TTm4iJPgFOfMV0WTJ0gJx3iBVrnoLSGhS+hcSH58PUo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qzlZvQXDWhzLI0F4HE249slxRRFW0sfTuk70RWXopwzE/xa7Jv9r6KnQNRuINSr6wjnCAZfrMGIl1aOHMYZRhOIZfR3ccXFn370AKumg+kTHqLwnREyPDTy0MzQZxIEzAIfRtU1xD/t5vp2QEUUvBdH2SbgbBZtVe4fjsDkNFbw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VVPhhwFb; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="VVPhhwFb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18AC51F000E9; Thu, 30 Jul 2026 14:30:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785421810; bh=ecj9Klkx1HvmLw89J+9Bv5PlSNqderWoKd5GejjRFro=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=VVPhhwFbWSqrPAsCEojUPUKDLjTAV0kQZWPM7BlsXZkPVfVDqmEP90bgjaxlx2D+x I9LETM61ILTKccBeF84xzqm2iY4PmxhfNr6OBhkRMYXL17c5RpsFN8pBzNzo+GK8vi Z7L8xqLoW6+1gLvvO1Lm1hReSN0qoq/m2o4DS70Q= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Suraj Kandpal , =?UTF-8?q?Micha=C5=82=20Grzelak?= , Rodrigo Vivi , Sasha Levin Subject: [PATCH 7.1 221/744] drm/i915/backlight: Remove DP_EDP_BACKLIGHT_AUX_ENABLE_CAP check for DPCD backlight Date: Thu, 30 Jul 2026 16:08:14 +0200 Message-ID: <20260730141448.980760670@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141444.267951807@linuxfoundation.org> References: <20260730141444.267951807@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 7.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Suraj Kandpal [ Upstream commit a411ea4a87162898d2a0547fdfb721ddb7626be3 ] Turns out some panels allow only AUX based backlight by just setting the DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP and not setting the DP_EDP_BACKLIGHT_AUX_ENABLE_CAP. If we make DP_EDP_BACKLIGHT_AUX_ENABLE_CAP a necessity for AUX based DPCD backlight these panels loose the ability to manipulate backlight via AUX, especially ones with no PWM controller. Remove this check from function so that panels who do not advertise DP_EDP_BACKLIGHT_AUX_ENABLE_CAP but advertise DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP are able to manipulate backlight again. Fixes: ed8be780bdbc ("drm/i915/backlight: Fix VESA backlight possible check condition") Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/16507 Signed-off-by: Suraj Kandpal Reviewed-by: Michał Grzelak Link: https://patch.msgid.link/20260716030959.436430-1-suraj.kandpal@intel.com (cherry picked from commit 7d594b24c915afb4b0c5fb8875403253daef5b24) Signed-off-by: Rodrigo Vivi Signed-off-by: Sasha Levin --- drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 7 +------ 1 file changed, 1 insertion(+), 6 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 7a6c07f6aaeb4b..266e042e00237c 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c @@ -615,12 +615,7 @@ check_if_vesa_backlight_possible(struct intel_dp *intel_dp) int ret; u8 bit_min, bit_max; - /* - * Since we only support Fully AUX Based VESA Backlight interface make sure - * backlight enable is possible via AUX along with backlight adjustment - */ - if (!(intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP && - intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) + if (!(intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) return false; ret = drm_dp_dpcd_read_byte(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &bit_min); -- 2.53.0