From patchwork Tue Jan 31 22:18:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 13123500 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 3CFAEC38142 for ; Tue, 31 Jan 2023 22:22:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229884AbjAaWW6 (ORCPT ); Tue, 31 Jan 2023 17:22:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51484 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231765AbjAaWW5 (ORCPT ); Tue, 31 Jan 2023 17:22:57 -0500 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D42785AB78 for ; Tue, 31 Jan 2023 14:22:21 -0800 (PST) Received: by mail-pj1-x102c.google.com with SMTP id mi9so6400592pjb.4 for ; Tue, 31 Jan 2023 14:22:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=j5glDXJkyFINglXsI3CpTvLcxwtU2p5GQD+LTvj3ho8=; b=MGYqySJ7a5kOGrLxSVQTPuNDc/2i1t8bijwCZ2YqVvkywI/2SY7K2dp5DEpanE58ou 5CI8vflM9byl63JTOFbRovm/6YmyFXqPx9tiYqmFZa711b972HDbYoaOpZi+myKKl/ih PI4VRMMdTjfoaCIDpIh1gU69YoQ7G4ejpB6rU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=j5glDXJkyFINglXsI3CpTvLcxwtU2p5GQD+LTvj3ho8=; b=jt0IKMr19cZPROWyeqwgwcSktEVJn6D4mRRWIh7f0mfN6gxEIFFJa3PtIcfuIbRm2y RoS2vS1CRTlzKM7am9wcjYyJMWAEMUK3SM+StkPDNkhcLggxBGaFDztKvch1Mxabj5D0 BWl4dDsayqviC/+gwTkM+cbN5Y4cnaQtQc7Yag2nzIg/jzgJ4Nw7yM1P8cbEWxjy/SXY VtoLqvaO3eJxggnjnP9n2wJvZG/C+cAI041l0m4o52u1yhzGh3JmhpeJJc9gbzXtrFIl 17PDsxkgLd1BXG+tBDlrCzWxwycmJ2vZ1BoNlKCcFylN7AhlccRqUC5SfN32ZuVRr7ql 9+7g== X-Gm-Message-State: AO0yUKXR8F0+75Wgig2WTq9wlta/OW0w7ATxrDLxeEcIHvzRFlT5ZAPa ttbMGrjjtepAO5LiDNVwrInFHQ== X-Google-Smtp-Source: AK7set/vdtVQvcQCXnftetWCbiq+pqLmSdMtnxFVEzrxkzoFDK72yZdFiwd4rzHSNyHuN5/l24rnFw== X-Received: by 2002:a17:902:f68b:b0:196:8158:fa8c with SMTP id l11-20020a170902f68b00b001968158fa8cmr765818plg.11.1675203739996; Tue, 31 Jan 2023 14:22:19 -0800 (PST) Received: from tictac2.mtv.corp.google.com ([2620:15c:9d:2:138e:73d3:502:64f]) by smtp.gmail.com with ESMTPSA id d18-20020a170903231200b0019339f3368asm10377471plh.3.2023.01.31.14.22.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 31 Jan 2023 14:22:19 -0800 (PST) From: Douglas Anderson To: dri-devel@lists.freedesktop.org, Rob Clark , Abhinav Kumar , Dmitry Baryshkov Cc: Andrzej Hajda , Laurent Pinchart , Sean Paul , Jonas Karlman , Vinod Koul , Robert Foss , linux-arm-msm@vger.kernel.org, Daniel Vetter , David Airlie , freedreno@lists.freedesktop.org, Stephen Boyd , Neil Armstrong , Jernej Skrabec , Dave Stevenson , Douglas Anderson , linux-kernel@vger.kernel.org Subject: [RFT PATCH v2 2/3] drm/msm/dsi: Stop unconditionally powering up DSI hosts at modeset Date: Tue, 31 Jan 2023 14:18:25 -0800 Message-Id: <20230131141756.RFT.v2.2.I4cfeab9d0e07e98ead23dd0736ab4461e6c69002@changeid> X-Mailer: git-send-email 2.39.1.456.gfc5497dd1b-goog In-Reply-To: <20230131141756.RFT.v2.1.I723a3761d57ea60c5dd754c144aed6c3b2ea6f5a@changeid> References: <20230131141756.RFT.v2.1.I723a3761d57ea60c5dd754c144aed6c3b2ea6f5a@changeid> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org In commit 7d8e9a90509f ("drm/msm/dsi: move DSI host powerup to modeset time"), we moved powering up DSI hosts to modeset time. This wasn't because it was an elegant design, but there were no better options. That commit actually ended up breaking ps8640, and thus was born commit ec7981e6c614 ("drm/msm/dsi: don't powerup at modeset time for parade-ps8640") as a temporary hack to un-break ps8640 by moving it to the old way of doing things. It turns out that ps8640 _really_ doesn't like its pre_enable() function to be called after dsi_mgr_bridge_power_on(). Specifically (from experimentation, not because I have any inside knowledge), it looks like the assertion of "RST#" in the ps8640 runtime resume handler seems like it's not allowed to happen after dsi_mgr_bridge_power_on() Recently, Dave Stevenson's series landed allowing bridges some control over pre_enable ordering. The meaty commit for our purposes is commit 4fb912e5e190 ("drm/bridge: Introduce pre_enable_prev_first to alter bridge init order"). As documented by that series, if a bridge doesn't set "pre_enable_prev_first" then we should use the old ordering. Now that we have the commit ("drm/bridge: tc358762: Set pre_enable_prev_first") we can go back to the old ordering, which also allows us to remove the ps8640 special case. One last note is that even without reverting commit 7d8e9a90509f ("drm/msm/dsi: move DSI host powerup to modeset time"), if you _just_ revert the ps8640 special case and try it out then it doesn't seem to fail anymore. I spent time bisecting / debugging this and it turns out to be mostly luck, so we still want this patch to make sure it's solid. Specifically the reason it sorta works these days is because we implemented wait_hpd_asserted() in ps8640 now, plus the magic of "pm_runtime" autosuspend. The fact that we have wait_hpd_asserted() implemented means that we actually power the bridge chip up just a wee bit earlier and then the bridge happens to stay on because of autosuspend and thus ends up powered before dsi_mgr_bridge_power_on(). Cc: Dave Stevenson Cc: Dmitry Baryshkov Cc: Abhinav Kumar Signed-off-by: Douglas Anderson Reviewed-by: Abhinav Kumar Reviewed-by: Dmitry Baryshkov --- Changes in v2: - Don't fold dsi_mgr_bridge_power_on() back into dsi_mgr_bridge_pre_enable() drivers/gpu/drm/msm/dsi/dsi_manager.c | 38 +-------------------------- 1 file changed, 1 insertion(+), 37 deletions(-) diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c index 1bbac72dad35..2197a54b9b96 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c @@ -34,32 +34,6 @@ static struct msm_dsi_manager msm_dsim_glb; #define IS_SYNC_NEEDED() (msm_dsim_glb.is_sync_needed) #define IS_MASTER_DSI_LINK(id) (msm_dsim_glb.master_dsi_link_id == id) -#ifdef CONFIG_OF -static bool dsi_mgr_power_on_early(struct drm_bridge *bridge) -{ - struct drm_bridge *next_bridge = drm_bridge_get_next_bridge(bridge); - - /* - * If the next bridge in the chain is the Parade ps8640 bridge chip - * then don't power on early since it seems to violate the expectations - * of the firmware that the bridge chip is running. - * - * NOTE: this is expected to be a temporary special case. It's expected - * that we'll eventually have a framework that allows the next level - * bridge to indicate whether it needs us to power on before it or - * after it. When that framework is in place then we'll use it and - * remove this special case. - */ - return !(next_bridge && next_bridge->of_node && - of_device_is_compatible(next_bridge->of_node, "parade,ps8640")); -} -#else -static inline bool dsi_mgr_power_on_early(struct drm_bridge *bridge) -{ - return true; -} -#endif - static inline struct msm_dsi *dsi_mgr_get_dsi(int id) { return msm_dsim_glb.dsi[id]; @@ -265,12 +239,6 @@ static void dsi_mgr_bridge_power_on(struct drm_bridge *bridge) 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 bonded DSI */ - if (is_bonded_dsi && !IS_MASTER_DSI_LINK(id)) - return; ret = dsi_mgr_phy_enable(id, phy_shared_timings); if (ret) @@ -327,8 +295,7 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge) if (is_bonded_dsi && !IS_MASTER_DSI_LINK(id)) return; - if (!dsi_mgr_power_on_early(bridge)) - dsi_mgr_bridge_power_on(bridge); + dsi_mgr_bridge_power_on(bridge); ret = msm_dsi_host_enable(host); if (ret) { @@ -438,9 +405,6 @@ static void dsi_mgr_bridge_mode_set(struct drm_bridge *bridge, msm_dsi_host_set_display_mode(host, adjusted_mode); if (is_bonded_dsi && other_dsi) msm_dsi_host_set_display_mode(other_dsi->host, adjusted_mode); - - if (dsi_mgr_power_on_early(bridge)) - dsi_mgr_bridge_power_on(bridge); } static enum drm_mode_status dsi_mgr_bridge_mode_valid(struct drm_bridge *bridge,