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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 E3FC6C433EF for ; Thu, 9 Sep 2021 11:41:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C44CC611AF for ; Thu, 9 Sep 2021 11:41:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235655AbhIILmT (ORCPT ); Thu, 9 Sep 2021 07:42:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:45492 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235448AbhIILmR (ORCPT ); Thu, 9 Sep 2021 07:42:17 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C2C4661100; Thu, 9 Sep 2021 11:41:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631187668; bh=84vvJMs9BQP/RnsgF6DIVjbTghk68ob7G2Kt8qsDxRc=; h=From:To:Cc:Subject:Date:From; b=BBUBwCFhZn2WuFf45v+A5/brjj24qbG/qRN6sLAcFoJycNGyjlAKWwJCgtIaK28xp UZulA/X66t/f2v4pb/P20LbFx2MW6aECCsX9HAqYinQzyJWYTw31ZRAKu2VbMFUged uEHbvaABmN12dNSHXeBz12v4w/xT7brdSnE9g1qMHnk3WJtEPa0xBBTPcBtm5RbWbl QBZCm9TThARbrSp8coh518z/nlxcP7esGug7T5NGWK0c4ZHpNVeKJ/dfG139/Z+opC Z4ymOgSDR9YtdIIkX+ckU8l6WYZ1QfSwFuUksV3IrQBLoydhTqz3o1nc1E6iuneFkv VvEOQp9P1a5fQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Douglas Anderson , Andrzej Hajda , Bjorn Andersson , Sasha Levin , dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 5.14 001/252] drm/bridge: ti-sn65dsi86: Don't read EDID blob over DDC Date: Thu, 9 Sep 2021 07:36:55 -0400 Message-Id: <20210909114106.141462-1-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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); -- 2.30.2