From patchwork Fri Nov 8 21:28:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephan Gerhold X-Patchwork-Id: 11235617 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6CBCC1515 for ; Fri, 8 Nov 2019 21:29:13 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 563EE2084D for ; Fri, 8 Nov 2019 21:29:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 563EE2084D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gerhold.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 707136FA91; Fri, 8 Nov 2019 21:29:12 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mo6-p01-ob.smtp.rzone.de (mo6-p01-ob.smtp.rzone.de [IPv6:2a01:238:20a:202:5301::5]) by gabe.freedesktop.org (Postfix) with ESMTPS id E4D096FA90; Fri, 8 Nov 2019 21:29:10 +0000 (UTC) X-RZG-AUTH: ":P3gBZUipdd93FF5ZZvYFPugejmSTVR2nRPhVORvLd4SsytBXQrEOHTIXsMnvtxdYcg==" X-RZG-CLASS-ID: mo00 Received: from localhost.localdomain by smtp.strato.de (RZmta 44.29.0 AUTH) with ESMTPSA id e07688vA8LT6tLL (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (curve secp521r1 with 521 ECDH bits, eq. 15360 bits RSA)) (Client did not present a certificate); Fri, 8 Nov 2019 22:29:06 +0100 (CET) From: Stephan Gerhold To: Rob Clark , Sean Paul Subject: [PATCH] drm/msm/dsi: Delay drm_panel_enable() until dsi_mgr_bridge_enable() Date: Fri, 8 Nov 2019 22:28:40 +0100 Message-Id: <20191108212840.13586-1-stephan@gerhold.net> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1573248548; s=strato-dkim-0002; d=gerhold.net; h=Message-Id:Date:Subject:Cc:To:From:X-RZG-CLASS-ID:X-RZG-AUTH:From: Subject:Sender; bh=RpCrO/BdsXbNks/Ok4F1Wqjf9N5GuN0H6cCDR5uSLF0=; b=FVW+PId/VIUw0CtYzhhpGfUC5M1i61G78o3p41B5qNzMtDr8RJjFDa6lb7Fo/PU7ud BPMf6hEj2lbGZMBm1jZjRmSArKvyo6bNIK46TuLv2EE1uy01cess8OKpvROsm2MFUD8p hVMJjaad2ZJg9LPIq0nrBEj39lJ2z4XOIvr4PBLULUebs/kluhXW+Uygrz6+lRjW3ODH STFsb8khtuX2dK3RJkuiJpUP1f+AIBJdr4bcb20HmvmAwZR53hLs1v9wyOt6W6tbGRnt zysEEZsr4H+eMOYdDc7FhwY7Rc/J1f2xjpKobDOHd4zRfZ9IMgQCFFXaseL2SmMW1pRL EdhQ== X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jasper Korten , Hai Li , Stephan Gerhold , David Airlie , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" At the moment, the MSM DSI driver calls drm_panel_enable() rather early from the DSI bridge pre_enable() function. At this point, the encoder (e.g. MDP5) is not enabled, so we have not started transmitting video data. However, the drm_panel_funcs documentation states that enable() should be called on the panel *after* video data is being transmitted: The .prepare() function is typically called before the display controller starts to transmit video data. [...] After the display controller has started transmitting video data, it's safe to call the .enable() function. This will typically enable the backlight to make the image on screen visible. Calling drm_panel_enable() too early causes problems for some panels: The TFT LCD panel used in the Samsung Galaxy Tab A 9.7 (2015) (APQ8016) uses the MIPI_DCS_SET_DISPLAY_BRIGHTNESS command to control backlight/brightness of the screen. The enable sequence is therefore: drm_panel_enable() drm_panel_funcs.enable(): backlight_enable() backlight_ops.update_status(): mipi_dsi_dcs_set_display_brightness(dsi, bl->props.brightness); The panel seems to silently ignore the MIPI_DCS_SET_DISPLAY_BRIGHTNESS command if it is sent too early. This prevents setting the initial brightness, causing the display to be enabled with minimum brightness instead. Adding various delays in the panel initialization code does not result in any difference. On the other hand, moving drm_panel_enable() to dsi_mgr_bridge_enable() fixes the problem, indicating that the panel requires the video stream to be active before the brightness command is accepted. Therefore: Move drm_panel_enable() to dsi_mgr_bridge_enable() to delay calling it until video data is being transmitted. Move drm_panel_disable() to dsi_mgr_bridge_disable() for similar reasons. (This is not strictly required for the panel affected above...) Tested-by: Jasper Korten Signed-off-by: Stephan Gerhold Tested-by: Jeffrey Hugo Reviewed-by: Jeffrey Hugo --- Since this is a core change I thought it would be better to send this early. I believe Jasper still wants to finish some other changes before submitting the initial device tree for the Samsung Galaxy Tab A 9.7 (2015). ;) I also tested it on msm8916-samsung-a5u-eur, its display is working fine with or without this patch. --- drivers/gpu/drm/msm/dsi/dsi_manager.c | 62 ++++++++++++++++++--------- 1 file changed, 41 insertions(+), 21 deletions(-) diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c index 271aa7bbca92..eea108865cd3 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c @@ -432,20 +432,8 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge) } } - if (panel) { - ret = drm_panel_enable(panel); - if (ret) { - pr_err("%s: enable panel %d failed, %d\n", __func__, id, - ret); - goto panel_en_fail; - } - } - return; -panel_en_fail: - if (is_dual_dsi && msm_dsi1) - msm_dsi_host_disable(msm_dsi1->host); host1_en_fail: msm_dsi_host_disable(host); host_en_fail: @@ -464,12 +452,51 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge) static void dsi_mgr_bridge_enable(struct drm_bridge *bridge) { - DBG(""); + int id = dsi_mgr_bridge_get_id(bridge); + struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id); + struct drm_panel *panel = msm_dsi->panel; + bool is_dual_dsi = IS_DUAL_DSI(); + int ret; + + DBG("id=%d", id); + if (!msm_dsi_device_connected(msm_dsi)) + return; + + /* Do nothing with the host if it is slave-DSI in case of dual DSI */ + if (is_dual_dsi && !IS_MASTER_DSI_LINK(id)) + return; + + if (panel) { + ret = drm_panel_enable(panel); + if (ret) { + pr_err("%s: enable panel %d failed, %d\n", __func__, id, + ret); + } + } } static void dsi_mgr_bridge_disable(struct drm_bridge *bridge) { - DBG(""); + int id = dsi_mgr_bridge_get_id(bridge); + struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id); + struct drm_panel *panel = msm_dsi->panel; + bool is_dual_dsi = IS_DUAL_DSI(); + int ret; + + DBG("id=%d", id); + if (!msm_dsi_device_connected(msm_dsi)) + return; + + /* Do nothing with the host if it is slave-DSI in case of dual DSI */ + if (is_dual_dsi && !IS_MASTER_DSI_LINK(id)) + return; + + if (panel) { + ret = drm_panel_disable(panel); + if (ret) + pr_err("%s: Panel %d OFF failed, %d\n", __func__, id, + ret); + } } static void dsi_mgr_bridge_post_disable(struct drm_bridge *bridge) @@ -495,13 +522,6 @@ static void dsi_mgr_bridge_post_disable(struct drm_bridge *bridge) if (is_dual_dsi && !IS_MASTER_DSI_LINK(id)) goto disable_phy; - if (panel) { - ret = drm_panel_disable(panel); - if (ret) - pr_err("%s: Panel %d OFF failed, %d\n", __func__, id, - ret); - } - ret = msm_dsi_host_disable(host); if (ret) pr_err("%s: host %d disable failed, %d\n", __func__, id, ret);