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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3D74CDB474 for ; Mon, 23 Oct 2023 11:14:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233680AbjJWLOZ (ORCPT ); Mon, 23 Oct 2023 07:14:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229880AbjJWLOY (ORCPT ); Mon, 23 Oct 2023 07:14:24 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5622192 for ; Mon, 23 Oct 2023 04:14:23 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AD7CC433C7; Mon, 23 Oct 2023 11:14:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698059663; bh=tmW/nX7+6CN8DgBthDCqJ6YaXZHP6i+hBwZQ5FvZwz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jEfiLa3jI5gw65d+936u4cco3LFxlNwoNjdW3sBROztDAyk35VfnSRjAG7CBvxgoM Difkxph/QMzJwRZMSyjiud5+vIs4nvhXblJm/qKZLc45LRi/Io9T+iaf3e9z8/TrAV MFoqzUJcGdhJQibrRmLlk6uFmqPMRWxjsBpd0CyE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Abhinav Kumar , Dmitry Baryshkov , Sasha Levin Subject: [PATCH 4.19 11/98] drm/msm/dsi: skip the wait for video mode done if not applicable Date: Mon, 23 Oct 2023 12:56:00 +0200 Message-ID: <20231023104813.980754071@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231023104813.580375891@linuxfoundation.org> References: <20231023104813.580375891@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Abhinav Kumar [ Upstream commit ab483e3adcc178254eb1ce0fbdfbea65f86f1006 ] dsi_wait4video_done() API waits for the DSI video mode engine to become idle so that we can transmit the DCS commands in the beginning of BLLP. However, with the current sequence, the MDP timing engine is turned on after the panel's pre_enable() callback which can send out the DCS commands needed to power up the panel. During those cases, this API will always timeout and print out the error spam leading to long bootup times and log flooding. Fix this by checking if the DSI video engine was actually busy before waiting for it to become idle otherwise this is a redundant wait. changes in v2: - move the reg read below the video mode check - minor fixes in commit text Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/34 Fixes: a689554ba6ed ("drm/msm: Initial add DSI connector support") Signed-off-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/557853/ Link: https://lore.kernel.org/r/20230915204426.19011-1-quic_abhinavk@quicinc.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/msm/dsi/dsi_host.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index 059578faa1c6d..5f4dd3659bf96 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -1059,9 +1059,21 @@ static void dsi_wait4video_done(struct msm_dsi_host *msm_host) static void dsi_wait4video_eng_busy(struct msm_dsi_host *msm_host) { + u32 data; + if (!(msm_host->mode_flags & MIPI_DSI_MODE_VIDEO)) return; + data = dsi_read(msm_host, REG_DSI_STATUS0); + + /* if video mode engine is not busy, its because + * either timing engine was not turned on or the + * DSI controller has finished transmitting the video + * data already, so no need to wait in those cases + */ + if (!(data & DSI_STATUS0_VIDEO_MODE_ENGINE_BUSY)) + return; + if (msm_host->power_on && msm_host->enabled) { dsi_wait4video_done(msm_host); /* delay 4 ms to skip BLLP */ -- 2.40.1