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 D8C09C54E68 for ; Mon, 18 Mar 2024 02:06:56 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 474D610F180; Mon, 18 Mar 2024 02:06:56 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="W7sMgtYp"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.21]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3637710F180 for ; Mon, 18 Mar 2024 02:06:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1710727614; x=1742263614; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=XEM/Y1H5PLPu/Sk0r62Cyraqdaw1A3qZ8mkHlYPLMmI=; b=W7sMgtYpypXfRtqLyAjDGVsl1UYU2mYZzXpyumazOtKhx8AQnqKHfMuo qR4lPlFarwhUoSRBh22VAVGtKy8adafrxDZqYkM2roAATJxOPngcg790k A+AdQitZFnL3wbVUEZ6ksFogq90i3GTz26psbaSk5ZZfYaHbjy+CYnNZt bo/oyi3puGPQsLgskFs3jSTfpi5LBLLJzDlQjTtrEhaSf4bZAbQsOJ5WY wrP1SwKFO43Slw3cVdJbe1UhBAx4g/fDDmkDHO8ReFyUCt1Kb235MhaYl qkk5Ch6PKAszobwXsqUZJEFT0T3GQ9V1KEzruAt9FV1aTa0CwubZqFJY7 A==; X-IronPort-AV: E=McAfee;i="6600,9927,11016"; a="5463266" X-IronPort-AV: E=Sophos;i="6.07,133,1708416000"; d="scan'208";a="5463266" Received: from fmviesa010.fm.intel.com ([10.60.135.150]) by orvoesa113.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Mar 2024 19:06:53 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,133,1708416000"; d="scan'208";a="13209990" Received: from gyu3-linux.itwn.intel.com ([10.225.64.197]) by fmviesa010.fm.intel.com with ESMTP; 17 Mar 2024 19:06:51 -0700 From: gareth.yu@intel.com To: intel-gfx@lists.freedesktop.org Cc: Gareth Yu Subject: [PATCH] drm/i915/display: Fixed a screen flickering when turning on display from off Date: Mon, 18 Mar 2024 10:15:33 +0800 Message-Id: <20240318021533.348354-1-gareth.yu@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240306031348.1344034-1-gareth.yu@intel.com> References: <20240306031348.1344034-1-gareth.yu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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" From: Gareth Yu Turn on the panel from zero brightness of the last state, the panel was set a maximum PWM in the flow. Once the panel initialization is completed, the backlight is restored to xero brightness. There is a flckering generated. This flicker happens in "Screen dimming and power off" of Google's design and resume from sleep. The sample of DMESG is below. (suspend) [53949.248875] i915 0000:00:02.0: [drm:intel_edp_backlight_off] [53949.452046] i915 0000:00:02.0: [drm:intel_backlight_set_pwm_level] set backlight PWM = 0 (wakeup) [53986.067356] i915 0000:00:02.0: [drm:intel_edp_backlight_on] [53986.067367] i915 0000:00:02.0: [drm:intel_backlight_enable] pipe A [53986.067476] i915 0000:00:02.0: [drm:intel_backlight_set_pwm_level] set backlight PWM = 96000 [53986.119766] backlight intel_backlight: PM: calling backlight_resume+0x0/0x7a @ 4916, parent: card0-eDP-1 [53986.119781] backlight intel_backlight: PM: backlight_resume+0x0/0x7a returned 0 after 0 usecs [53986.220068] [drm:intel_backlight_device_update_status] updating intel_backlight, brightness=26321/96000 [53986.220086] i915 0000:00:02.0: [drm:intel_panel_actually_set_backlight] set backlight level = 27961 Set the brightness to the minimum value when the brightness is less or equal to the minimum value to mitigate this flickering. Cc : Tejas Upadhyay Cc : Matt Roper Cc : Ville Syrjälä Signed-off-by: Gareth Yu --- drivers/gpu/drm/i915/display/intel_backlight.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/drm/i915/display/intel_backlight.c index 3f3cd944a1c5..1cfac72aacc6 100644 --- a/drivers/gpu/drm/i915/display/intel_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_backlight.c @@ -761,7 +761,7 @@ static void __intel_backlight_enable(const struct intel_crtc_state *crtc_state, WARN_ON(panel->backlight.max == 0); - if (panel->backlight.level <= panel->backlight.min) { + if (panel->backlight.level < panel->backlight.min) { panel->backlight.level = panel->backlight.max; if (panel->backlight.device) panel->backlight.device->props.brightness = -- 2.25.1