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 90D63C7115B for ; Fri, 20 Jun 2025 06:35:31 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 28BC210EB01; Fri, 20 Jun 2025 06:35:31 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="hKYcdG6s"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) by gabe.freedesktop.org (Postfix) with ESMTPS id 468D710EAF6; Fri, 20 Jun 2025 06:35:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1750401330; x=1781937330; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=aAUdtDjx+DMwpFK/QcnjcG5XKBnwy92g+X1LYbm6ox4=; b=hKYcdG6s69FlH9h7C9tAEobKVg7zuhnCkocxtkb2vro8epc4rAE3r2n1 GFgYH1/nARLoqfCT6AGEg6ESReeK0A5kcMrzLisLAqYhHQGswuE2+0lqK K/C6Rn/UPMLfaLIh2bZ/er50x8U6c7yITFchqjEDzAFYXpWfXfWqJXphx 3kuuScMjkR/3ecO3MDVrXOE11XobX2SShnodiYvhWSvJNtfvfboWsqol0 rc83QVRhs4FYuE9j/yjBe1brUXJbl19iAHaan9xmmiF7e5F0pkvLTYjvJ rPn408Syhusar4tmScieY7p9zrnAF+Lpy1VgSDvGh85E2P5vQ5uN4OjsC w==; X-CSE-ConnectionGUID: WXHfnSKTTQuM6jFSA0Jhrw== X-CSE-MsgGUID: y3WWUypXRd6dymCegZlOLw== X-IronPort-AV: E=McAfee;i="6800,10657,11469"; a="63701872" X-IronPort-AV: E=Sophos;i="6.16,250,1744095600"; d="scan'208";a="63701872" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jun 2025 23:35:29 -0700 X-CSE-ConnectionGUID: kpNVppXpRNenxXKgO8PBQA== X-CSE-MsgGUID: 4sSW8VICRiWJJJ82hD+n4w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,250,1744095600"; d="scan'208";a="174440323" Received: from kandpal-x299-ud4-pro.iind.intel.com ([10.190.239.10]) by fmviesa002.fm.intel.com with ESMTP; 19 Jun 2025 23:35:27 -0700 From: Suraj Kandpal To: intel-xe@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org Cc: arun.r.murthy@intel.com, Suraj Kandpal Subject: [PATCH v3 06/13] drm/dp: Modify drm_edp_probe_state Date: Fri, 20 Jun 2025 12:04:38 +0530 Message-Id: <20250620063445.3603086-7-suraj.kandpal@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250620063445.3603086-1-suraj.kandpal@intel.com> References: <20250620063445.3603086-1-suraj.kandpal@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Modify drm_edp_probe_state to read current level from DP_EDP_PANEL_TARGET_LUMINANCE_VALUE. We divide it by 1000 since the value in this register is in millinits. --v2 -Add comment on the unit sent back [Arun] Signed-off-by: Suraj Kandpal Reviewed-by: Arun R Murthy --- drivers/gpu/drm/display/drm_dp_helper.c | 40 ++++++++++++++++++------- 1 file changed, 30 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c index daeb3bdc87a3..53f02dc6c3f1 100644 --- a/drivers/gpu/drm/display/drm_dp_helper.c +++ b/drivers/gpu/drm/display/drm_dp_helper.c @@ -4209,7 +4209,7 @@ drm_edp_backlight_probe_state(struct drm_dp_aux *aux, struct drm_edp_backlight_i u8 *current_mode) { int ret; - u8 buf[2]; + u8 buf[3]; u8 mode_reg; ret = drm_dp_dpcd_read_byte(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &mode_reg); @@ -4226,17 +4226,37 @@ drm_edp_backlight_probe_state(struct drm_dp_aux *aux, struct drm_edp_backlight_i if (*current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) { int size = 1 + bl->lsb_reg_used; - ret = drm_dp_dpcd_read_data(aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, buf, size); - if (ret < 0) { - drm_dbg_kms(aux->drm_dev, "%s: Failed to read backlight level: %d\n", - aux->name, ret); - return ret; + if (bl->luminance_set) { + ret = drm_dp_dpcd_read_data(aux, DP_EDP_PANEL_TARGET_LUMINANCE_VALUE, + buf, sizeof(buf)); + if (ret < 0) { + drm_dbg_kms(aux->drm_dev, + "%s: Failed to read backlight level: %d\n", + aux->name, ret); + return ret; } - if (bl->lsb_reg_used) - return (buf[0] << 8) | buf[1]; - else - return buf[0]; + /* + * Incase luminance is set we want to send the value back in nits but since + * DP_EDP_PANEL_TARGET_LUMINANCE stores values in millinits we need to divide + * by 1000. + */ + return (buf[0] | buf[1] << 8 | buf[2] << 16) / 1000; + } else { + ret = drm_dp_dpcd_read_data(aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, + buf, size); + if (ret < 0) { + drm_dbg_kms(aux->drm_dev, + "%s: Failed to read backlight level: %d\n", + aux->name, ret); + return ret; + } + + if (bl->lsb_reg_used) + return (buf[0] << 8) | buf[1]; + else + return buf[0]; + } } /* -- 2.34.1