From nobody Fri May 8 02:21:30 2026 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 3A873C433EF for ; Thu, 12 May 2022 20:52:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358488AbiELUwa (ORCPT ); Thu, 12 May 2022 16:52:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358481AbiELUw2 (ORCPT ); Thu, 12 May 2022 16:52:28 -0400 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE8D91BB991 for ; Thu, 12 May 2022 13:52:26 -0700 (PDT) Received: by mail-pf1-x435.google.com with SMTP id a11so5896821pff.1 for ; Thu, 12 May 2022 13:52:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=0Ies45XQh7ymdD5acJILStC2yG/IlgiJIKbLY52H88Q=; b=Zc+8sBWS1pojS7k/yPaJKk9BjzB/ATYdrEE1H/xsCuyenIYW19LxvPheqCeXWPmZrD OOdoPh+6HS1wB5oA53VwSqlqDOQqR1G1jmoJCMF8PDHBQPQX4IM6t2ImiFcbjqaLE5Nt EERMlp16x35JlLgCeCl/sSNUXfn8TWUZfRE+k= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=0Ies45XQh7ymdD5acJILStC2yG/IlgiJIKbLY52H88Q=; b=ADqRQdy56Gb/ZrXq/GEEFdVotFJvOrsFDDQ4oY3HFs99PODt0Z8wmfTEz15obw7TIS 9aVW8alHyT6OJufNsIy3aqW1oT8juPljZYhOfkCEd64WEzFPh37x5OWc4ceQF5rltEfi llJ0Sm3USfPkQHxF9ZmuDHmoAXGLU2QSkhkPltcpRk3BlfBewWrhrPKYz1hyheB3io2O eW+RlkIne3y9NeOBL6/0nesqH+HCaacL676Z0QjmKwsOEUHKVkRyuL1tMn0Gnm4KtZfB rm1RiZ/+eZAzZaW7e4bpgKIIc/RmKv6A+MdgtjP1opvUX/NEx8E4noQ+3Z60FZjVqHtq Jl2g== X-Gm-Message-State: AOAM533W25NaCGYPVfS1+nPrrEWmYWNG+E5oa/sgP2HRMNnQK5KcCxmf mhKJgoo++mavzNB/WXqKcC1OGA== X-Google-Smtp-Source: ABdhPJxegJvQdMeDYnLXr1pjy2t9mHEjDACmKnVCoEdKhoZ9MnnfrVqDUATBEGvOT8sgCIE9Jo6b7Q== X-Received: by 2002:a63:1d5f:0:b0:3c6:e822:2eb1 with SMTP id d31-20020a631d5f000000b003c6e8222eb1mr1122541pgm.99.1652388746275; Thu, 12 May 2022 13:52:26 -0700 (PDT) Received: from tictac2.mtv.corp.google.com ([2620:15c:202:201:1ee3:ea22:908:c2b5]) by smtp.gmail.com with ESMTPSA id q15-20020a170902a3cf00b0015eddb8e450sm370681plb.25.2022.05.12.13.52.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 May 2022 13:52:25 -0700 (PDT) From: Douglas Anderson To: Rob Clark , Abhinav Kumar , Dmitry Baryshkov Cc: Dave Stevenson , Douglas Anderson , Bjorn Andersson , Daniel Vetter , David Airlie , Sean Paul , Stephen Boyd , Vinod Koul , dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3] drm/msm/dsi: only powerup at modeset time if "early_poweron" modparam Date: Thu, 12 May 2022 13:52:18 -0700 Message-Id: <20220512135134.v3.1.Ia196e35ad985059e77b038a41662faae9e26f411@changeid> X-Mailer: git-send-email 2.36.0.550.gb090851708-goog MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Commit 7d8e9a90509f ("drm/msm/dsi: move DSI host powerup to modeset time") caused sc7180 Chromebooks that use the parade-ps8640 bridge chip to fail to turn the display back on after it turns off. Unfortunately, it doesn't look easy to fix the parade-ps8640 driver to handle the new power sequence. The Linux driver has almost nothing in it and most of the logic for this bridge chip is in black-box firmware that the bridge chip uses. Also unfortunately, reverting the patch will break "tc358762". The long term solution here is probably Dave Stevenson's series [1] that would give more flexibility. However, that is likely not a quick fix. For the short term, let's introduce a module parameter that selects between the two behaviors. This is a short term hack but at least can keep both users working. We'll default the value of the module parameter to the old behavior. Given that the old behavior has existed for longer it's probably a safer default. [1] https://lore.kernel.org/r/cover.1646406653.git.dave.stevenson@raspberry= pi.com Fixes: 7d8e9a90509f ("drm/msm/dsi: move DSI host powerup to modeset time") Suggested-by: Dmitry Baryshkov Signed-off-by: Douglas Anderson Reviewed-by: Dmitry Baryshkov --- Changes in v3: - No longer a revert; now a module parameter. Changes in v2: - Remove the mud from my face. drivers/gpu/drm/msm/dsi/dsi_manager.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/ds= i/dsi_manager.c index 50b987658b1f..2bf4123ef5df 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c @@ -34,6 +34,10 @@ 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 =3D=3D id) =20 +bool early_poweron; +MODULE_PARM_DESC(early_poweron, "Power DSI controller early"); +module_param(early_poweron, bool, 0600); + static inline struct msm_dsi *dsi_mgr_get_dsi(int id) { return msm_dsim_glb.dsi[id]; @@ -389,6 +393,9 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge= *bridge) if (is_bonded_dsi && !IS_MASTER_DSI_LINK(id)) return; =20 + if (!early_poweron) + dsi_mgr_bridge_power_on(bridge); + /* Always call panel functions once, because even for dual panels, * there is only one drm_panel instance. */ @@ -570,7 +577,8 @@ static void dsi_mgr_bridge_mode_set(struct drm_bridge *= bridge, if (is_bonded_dsi && other_dsi) msm_dsi_host_set_display_mode(other_dsi->host, adjusted_mode); =20 - dsi_mgr_bridge_power_on(bridge); + if (early_poweron) + dsi_mgr_bridge_power_on(bridge); } =20 static enum drm_mode_status dsi_mgr_bridge_mode_valid(struct drm_bridge *b= ridge, --=20 2.36.0.550.gb090851708-goog