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 X-Spam-Level: X-Spam-Status: No, score=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1C95C2B9F8 for ; Tue, 25 May 2021 00:03:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 81875613E6 for ; Tue, 25 May 2021 00:03:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230081AbhEYAFI (ORCPT ); Mon, 24 May 2021 20:05:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230012AbhEYAE2 (ORCPT ); Mon, 24 May 2021 20:04:28 -0400 Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4704CC06138F for ; Mon, 24 May 2021 17:02:54 -0700 (PDT) Received: by mail-pj1-x1032.google.com with SMTP id ml1-20020a17090b3601b029015f9b1ebce0so2881044pjb.5 for ; Mon, 24 May 2021 17:02:54 -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:in-reply-to:references :mime-version:content-transfer-encoding; bh=VG642XiPIrhSg91dKUHe6+GLs0ckaFTMQhwL7tvY4bg=; b=OkY29HZHat0AQRtLGeI/MZdbdm3GktcgWCM1ev4YHbx9Uow4RWiKsrboV2UWSY2bxi CrLb7CxaZFlYz25pyFwTAQb8IGSRw1EHN53sU/+e2sNW65F7kTFFeWPJzwQrENggUmZs fZV9A9uSSuTkzyL/OF2KlzCDJBJ4l17224jIA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=VG642XiPIrhSg91dKUHe6+GLs0ckaFTMQhwL7tvY4bg=; b=TLSU5fFmoYeFM2MSl4b5j1+W4DBRVMCkivoIW64A6B1EtEyLrIeO4NV3vJtzVCXsvH 45waVmXmIAok1Bsc3A76bYzsGK8+BD5PRGgu/U2HegoukeV34rrZ3UpsxybfU/f57ifJ BWYaMuorg4fbLXgY71vY8BgkS5QnwAdo/pxsqDvfTXpp2Xrgd0XW3br3T4fZ39kuf1Iv GQT5IEgssWwCIWbGv5EMC23Ej1wdcM2Hi2cwesU6AUfV9w1otPXieYN9KA85ed2rqVUE lC+I/ia8HwNHfQJkkAw7a+a7kLsgvTo0EKti3fcE2hQYqvbng+wt3EtW+ooasznrLhry hOXg== X-Gm-Message-State: AOAM532KaWagk0YsYEsErrBYsIFVpNwhsC2ZPPo0+x4JuGNe2nc7DwCt ZsSrx5XwXIagOFzr2Up6i7yQrA== X-Google-Smtp-Source: ABdhPJzt/q1SLUdgusC9g9GEJBytN/RWLJqF9WjNI2gRCXP+2W0YnOA9khIloFbX/FNQnvOXQ+mS4g== X-Received: by 2002:a17:90a:5d8e:: with SMTP id t14mr27224704pji.85.1621900973923; Mon, 24 May 2021 17:02:53 -0700 (PDT) Received: from tictac2.mtv.corp.google.com ([2620:15c:202:201:26d1:4df0:7cdf:ce13]) by smtp.gmail.com with ESMTPSA id f18sm10696741pjh.55.2021.05.24.17.02.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 May 2021 17:02:53 -0700 (PDT) From: Douglas Anderson To: Andrzej Hajda , Neil Armstrong , Laurent Pinchart , Jonas Karlman , Sam Ravnborg Cc: linux-arm-msm@vger.kernel.org, Linus W , Lyude Paul , Bjorn Andersson , Steev Klimaszewski , robdclark@chromium.org, Maarten Lankhorst , Thierry Reding , dri-devel@lists.freedesktop.org, Stanislav Lisovskiy , Stephen Boyd , Douglas Anderson , Daniel Vetter , David Airlie , Jernej Skrabec , Robert Foss , linux-kernel@vger.kernel.org Subject: [PATCH v8 10/11] drm/bridge: ti-sn65dsi86: Don't read EDID blob over DDC Date: Mon, 24 May 2021 17:01:58 -0700 Message-Id: <20210524165920.v8.10.I9330684c25f65bb318eff57f0616500f83eac3cc@changeid> X-Mailer: git-send-email 2.31.1.818.g46aad6cb9e-goog In-Reply-To: <20210525000159.3384921-1-dianders@chromium.org> References: <20210525000159.3384921-1-dianders@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org This is really just a revert of commit 58074b08c04a ("drm/bridge: ti-sn65dsi86: Read EDID blob over DDC"), resolving conflicts. The old code failed to read the EDID properly in a very important case: before the bridge's pre_enable() was called. The way things need to work: 1. Read the EDID. 2. Based on the EDID, decide on video settings and pixel clock. 3. Enable the bridge w/ the desired settings. The way things were working: 1. Try to read the EDID but fail; fall back to hardcoded values. 2. Based on hardcoded values, decide on video settings and pixel clock. 3. Enable the bridge w/ the desired settings. 4. Try again to read the EDID, it works now! 5. Realize that the hardcoded settings weren't quite right. 6. Disable / reenable the bridge w/ the right settings. The reasons for the failures were twofold: a) Since we never ran the bridge chip's pre-enable then we never set the bit to ignore HPD. This meant the bridge chip didn't even _try_ to go out on the bus and communicate with the panel. b) Even if we fixed things to ignore HPD, the EDID still wouldn't read if the panel wasn't on. Instead of reverting the code, we could fix it to set the HPD bit and also power on the panel. However, it also works nicely to just let the panel code read the EDID. Now that we've split the driver up we can expose the DDC AUX channel bus to the panel node. The panel can take charge of reading the EDID. NOTE: in order for things to work, anyone that needs to read the EDID will need to instantiate their panel using the new DP AUX bus (AKA by listing their panel under the "aux-bus" node of the bridge chip in the device tree). In the future if we want to use the bridge chip to provide a full external DP port (which won't have a panel) then we will have to conditinally add EDID reading back in. Suggested-by: Andrzej Hajda Signed-off-by: Douglas Anderson Reviewed-by: Bjorn Andersson --- (no changes since v7) Changes in v7: - Adjusted commit message to talk about DP AUX bus. drivers/gpu/drm/bridge/ti-sn65dsi86.c | 22 ---------------------- 1 file changed, 22 deletions(-) diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 5263206792f6..b7453c80cdb8 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -126,7 +126,6 @@ * @connector: Our connector. * @host_node: Remote DSI node. * @dsi: Our MIPI DSI source. - * @edid: Detected EDID of eDP panel. * @refclk: Our reference clock. * @panel: Our panel. * @enable_gpio: The GPIO we toggle to enable the bridge. @@ -157,7 +156,6 @@ struct ti_sn65dsi86 { struct drm_dp_aux aux; struct drm_bridge bridge; struct drm_connector connector; - struct edid *edid; struct device_node *host_node; struct mipi_dsi_device *dsi; struct clk *refclk; @@ -406,24 +404,6 @@ connector_to_ti_sn65dsi86(struct drm_connector *connector) static int ti_sn_bridge_connector_get_modes(struct drm_connector *connector) { struct ti_sn65dsi86 *pdata = connector_to_ti_sn65dsi86(connector); - struct edid *edid = pdata->edid; - int num, ret; - - if (!edid) { - pm_runtime_get_sync(pdata->dev); - edid = pdata->edid = drm_get_edid(connector, &pdata->aux.ddc); - pm_runtime_put_autosuspend(pdata->dev); - } - - if (edid && drm_edid_is_valid(edid)) { - ret = drm_connector_update_edid_property(connector, edid); - if (!ret) { - num = drm_add_edid_modes(connector, edid); - if (num) - return num; - } - } - return drm_panel_get_modes(pdata->panel, connector); } @@ -1356,8 +1336,6 @@ static void ti_sn_bridge_remove(struct auxiliary_device *adev) mipi_dsi_device_unregister(pdata->dsi); } - kfree(pdata->edid); - drm_bridge_remove(&pdata->bridge); of_node_put(pdata->host_node); -- 2.31.1.818.g46aad6cb9e-goog