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 B971CC00A8F for ; Mon, 23 Oct 2023 11:29:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234008AbjJWL31 (ORCPT ); Mon, 23 Oct 2023 07:29:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234017AbjJWL3X (ORCPT ); Mon, 23 Oct 2023 07:29:23 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A39ABDF for ; Mon, 23 Oct 2023 04:29:21 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDD51C433C9; Mon, 23 Oct 2023 11:29:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698060561; bh=0DrDmamXYjc/gRiBrB8n019xDtOfxloEuWZ5G0MF/VE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AL5rynpVcJNfXPI29sIE1sK1UtKaoihyjHDM84M6W2L6CmG49FVTL4bfVVms9Fiu2 FdOZ64ahuCwz7R0bpAzCW5nPSTk7+jbtm7fMgxmD3PVzkup2dgL8dNDfgeH3Ja/NZD QEPEi7l6APMG2bH4Rudb8fL+opemZXsC+8LC0E4Y= 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 5.4 009/123] drm/msm/dsi: skip the wait for video mode done if not applicable Date: Mon, 23 Oct 2023 12:56:07 +0200 Message-ID: <20231023104818.044606690@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231023104817.691299567@linuxfoundation.org> References: <20231023104817.691299567@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 5.4-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 c59764f156f94..419cad31830ea 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -1051,9 +1051,21 @@ 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