From patchwork Mon Sep 13 13:13:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 510471 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=ham 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 75DABC433EF for ; Mon, 13 Sep 2021 14:30:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F9AD610CB for ; Mon, 13 Sep 2021 14:30:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345418AbhIMObh (ORCPT ); Mon, 13 Sep 2021 10:31:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:51244 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347037AbhIMOaJ (ORCPT ); Mon, 13 Sep 2021 10:30:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6B5B461B94; Mon, 13 Sep 2021 13:51:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631541060; bh=84vvJMs9BQP/RnsgF6DIVjbTghk68ob7G2Kt8qsDxRc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hQKoIsl6uNXWDH4MMQ8yEkVwyFvGye/hs9Uw4lUAsvPyXHZa1Au/rF6fquAVWc8bW Y5Ph1UhCdHT4HT0v4HHjdHWJKeZUDOVswO6j63WfFvLC0qzlzDGqYBnXbDgB1E0/+p oi9fle1ivL6Xd3BCD9eBqVLi+mZaDewKlBJZMUoc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrzej Hajda , Douglas Anderson , Bjorn Andersson , Sasha Levin Subject: [PATCH 5.14 147/334] drm/bridge: ti-sn65dsi86: Dont read EDID blob over DDC Date: Mon, 13 Sep 2021 15:13:21 +0200 Message-Id: <20210913131118.330293390@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210913131113.390368911@linuxfoundation.org> References: <20210913131113.390368911@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Douglas Anderson [ Upstream commit a70e558c151043ce46a5e5999f4310e0b3551f57 ] 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 Link: https://patchwork.freedesktop.org/patch/msgid/20210611101711.v10.9.I9330684c25f65bb318eff57f0616500f83eac3cc@changeid Signed-off-by: Sasha Levin --- 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 45a2969afb2b..aef850296756 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -124,7 +124,6 @@ * @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. @@ -154,7 +153,6 @@ 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; @@ -403,24 +401,6 @@ 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); } @@ -1358,8 +1338,6 @@ 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);