From nobody Sat Feb 7 23:47:54 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 BEA31EB64D9 for ; Sat, 17 Jun 2023 15:06:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234167AbjFQPG5 (ORCPT ); Sat, 17 Jun 2023 11:06:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229972AbjFQPGz (ORCPT ); Sat, 17 Jun 2023 11:06:55 -0400 Received: from vps.xff.cz (vps.xff.cz [195.181.215.36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72A6810D1 for ; Sat, 17 Jun 2023 08:06:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=xff.cz; s=mail; t=1687014409; bh=7l1Ay6Slm7w/z02wmZh7MS4AZDvT3URsKVMaUkBRKWk=; h=From:To:Cc:Subject:Date:From; b=YbHwSEMqkr1r4xf+lj6fOrMS4EQ4GFm3X/Y63KQ3qV6xHTrB487vgE9DIzmyn9sZa 1vqlVd051Pv51wgDZzvCiB+e5fSLgJWltPSaFKGRjaDPpcZWeoNaI9EKsumSHTroDr tcLpiYV36J2YOoSSznNRITPndz7OKuenPzxn8XhQ= From: =?UTF-8?q?Ond=C5=99ej=20Jirman?= To: linux-rockchip@lists.infradead.org Cc: Ondrej Jirman , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org (open list:DRM DRIVERS), linux-kernel@vger.kernel.org (open list) Subject: [PATCH] drm: bridge: dw-mipi-dsi: Fix enable/disable of DSI controller Date: Sat, 17 Jun 2023 17:06:33 +0200 Message-ID: <20230617150643.1808409-1-megi@xff.cz> 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" From: Ondrej Jirman Before this patch, booting to Linux VT and doing a simple: echo 2 > /sys/class/graphics/fb0/blank echo 0 > /sys/class/graphics/fb0/blank would result in failures to re-enable the panel. Mode set callback is called only once during boot in this scenario, while calls to enable/disable callbacks are balanced afterwards. The driver doesn't work unless userspace calls modeset before enabling the CRTC/connector. This patch moves enabling of the DSI host from mode_set into pre_enable callback, and removes some old hacks where this bridge driver is directly calling into other bridge driver's callbacks. pre_enable_prev_first flag is set on the panel's bridge so that panel drivers will get their prepare function called between DSI host's pre_enable and enable callbacks, so that they get a chance to perform panel setup while DSI host is already enabled in command mode. Otherwise panel's prepare would be called before DSI host is enabled, and any DSI communication used in prepare callback would fail. With all these changes, the enable/disable sequence is now well balanced, and host's and panel's callbacks are called in proper order documented in the drm_panel API documentation without needing the old hacks. (Mainly that panel->prepare is called when DSI host is ready to allow the panel driver to send DSI commands and vice versa during disable.) Tested on Pinephone Pro. Trace of the callbacks follows. Before: [ 1.253882] dw-mipi-dsi-rockchip ff960000.dsi: mode_set [ 1.290732] panel-himax-hx8394 ff960000.dsi.0: prepare [ 1.475576] dw-mipi-dsi-rockchip ff960000.dsi: enable [ 1.475593] panel-himax-hx8394 ff960000.dsi.0: enable echo 2 > /sys/class/graphics/fb0/blank [ 13.722799] panel-himax-hx8394 ff960000.dsi.0: disable [ 13.774502] dw-mipi-dsi-rockchip ff960000.dsi: post_disable [ 13.774526] panel-himax-hx8394 ff960000.dsi.0: unprepare echo 0 > /sys/class/graphics/fb0/blank [ 17.735796] panel-himax-hx8394 ff960000.dsi.0: prepare [ 17.923522] dw-mipi-dsi-rockchip ff960000.dsi: enable [ 17.923540] panel-himax-hx8394 ff960000.dsi.0: enable [ 17.944330] dw-mipi-dsi-rockchip ff960000.dsi: failed to write command F= IFO [ 17.944335] panel-himax-hx8394 ff960000.dsi.0: sending command 0xb9 fail= ed: -110 [ 17.944340] panel-himax-hx8394 ff960000.dsi.0: Panel init sequence faile= d: -110 echo 2 > /sys/class/graphics/fb0/blank [ 431.148583] panel-himax-hx8394 ff960000.dsi.0: disable [ 431.169259] dw-mipi-dsi-rockchip ff960000.dsi: failed to write command F= IFO [ 431.169268] panel-himax-hx8394 ff960000.dsi.0: Failed to enter sleep mod= e: -110 [ 431.169282] dw-mipi-dsi-rockchip ff960000.dsi: post_disable [ 431.169316] panel-himax-hx8394 ff960000.dsi.0: unprepare [ 431.169357] pclk_mipi_dsi0 already disabled echo 0 > /sys/class/graphics/fb0/blank [ 432.796851] panel-himax-hx8394 ff960000.dsi.0: prepare [ 432.981537] dw-mipi-dsi-rockchip ff960000.dsi: enable [ 432.981568] panel-himax-hx8394 ff960000.dsi.0: enable [ 433.002290] dw-mipi-dsi-rockchip ff960000.dsi: failed to write command F= IFO [ 433.002299] panel-himax-hx8394 ff960000.dsi.0: sending command 0xb9 fail= ed: -110 [ 433.002312] panel-himax-hx8394 ff960000.dsi.0: Panel init sequence faile= d: -110 Reviewed-by: Sam Ravnborg ----------------------------------------------------------------------- After: [ 1.248372] dw-mipi-dsi-rockchip ff960000.dsi: mode_set [ 1.248704] dw-mipi-dsi-rockchip ff960000.dsi: pre_enable [ 1.285377] panel-himax-hx8394 ff960000.dsi.0: prepare [ 1.468392] dw-mipi-dsi-rockchip ff960000.dsi: enable [ 1.468421] panel-himax-hx8394 ff960000.dsi.0: enable echo 2 > /sys/class/graphics/fb0/blank [ 16.210357] panel-himax-hx8394 ff960000.dsi.0: disable [ 16.261315] dw-mipi-dsi-rockchip ff960000.dsi: post_disable [ 16.261339] panel-himax-hx8394 ff960000.dsi.0: unprepare echo 0 > /sys/class/graphics/fb0/blank [ 19.161453] dw-mipi-dsi-rockchip ff960000.dsi: pre_enable [ 19.197869] panel-himax-hx8394 ff960000.dsi.0: prepare [ 19.382141] dw-mipi-dsi-rockchip ff960000.dsi: enable [ 19.382158] panel-himax-hx8394 ff960000.dsi.0: enable Signed-off-by: Ondrej Jirman --- drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 28 +++++++++++-------- 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/dr= m/bridge/synopsys/dw-mipi-dsi.c index b2efecf7d160..352c6829259a 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c @@ -265,6 +265,7 @@ struct dw_mipi_dsi { struct dw_mipi_dsi *master; /* dual-dsi master ptr */ struct dw_mipi_dsi *slave; /* dual-dsi slave ptr */ =20 + struct drm_display_mode mode; const struct dw_mipi_dsi_plat_data *plat_data; }; =20 @@ -332,6 +333,7 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host= *host, if (IS_ERR(bridge)) return PTR_ERR(bridge); =20 + bridge->pre_enable_prev_first =3D true; dsi->panel_bridge =3D bridge; =20 drm_bridge_add(&dsi->bridge); @@ -859,15 +861,6 @@ static void dw_mipi_dsi_bridge_post_atomic_disable(str= uct drm_bridge *bridge, */ dw_mipi_dsi_set_mode(dsi, 0); =20 - /* - * TODO Only way found to call panel-bridge post_disable & - * panel unprepare before the dsi "final" disable... - * This needs to be fixed in the drm_bridge framework and the API - * needs to be updated to manage our own call chains... - */ - if (dsi->panel_bridge->funcs->post_disable) - dsi->panel_bridge->funcs->post_disable(dsi->panel_bridge); - if (phy_ops->power_off) phy_ops->power_off(dsi->plat_data->priv_data); =20 @@ -942,15 +935,25 @@ static void dw_mipi_dsi_mode_set(struct dw_mipi_dsi *= dsi, phy_ops->power_on(dsi->plat_data->priv_data); } =20 +static void dw_mipi_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge, + struct drm_bridge_state *old_bridge_state) +{ + struct dw_mipi_dsi *dsi =3D bridge_to_dsi(bridge); + + /* Power up the dsi ctl into a command mode */ + dw_mipi_dsi_mode_set(dsi, &dsi->mode); + if (dsi->slave) + dw_mipi_dsi_mode_set(dsi->slave, &dsi->mode); +} + static void dw_mipi_dsi_bridge_mode_set(struct drm_bridge *bridge, const struct drm_display_mode *mode, const struct drm_display_mode *adjusted_mode) { struct dw_mipi_dsi *dsi =3D bridge_to_dsi(bridge); =20 - dw_mipi_dsi_mode_set(dsi, adjusted_mode); - if (dsi->slave) - dw_mipi_dsi_mode_set(dsi->slave, adjusted_mode); + /* Store the display mode for later use in pre_enable callback */ + memcpy(&dsi->mode, adjusted_mode, sizeof(dsi->mode)); } =20 static void dw_mipi_dsi_bridge_atomic_enable(struct drm_bridge *bridge, @@ -1004,6 +1007,7 @@ static const struct drm_bridge_funcs dw_mipi_dsi_brid= ge_funcs =3D { .atomic_duplicate_state =3D drm_atomic_helper_bridge_duplicate_state, .atomic_destroy_state =3D drm_atomic_helper_bridge_destroy_state, .atomic_reset =3D drm_atomic_helper_bridge_reset, + .atomic_pre_enable =3D dw_mipi_dsi_bridge_atomic_pre_enable, .atomic_enable =3D dw_mipi_dsi_bridge_atomic_enable, .atomic_post_disable =3D dw_mipi_dsi_bridge_post_atomic_disable, .mode_set =3D dw_mipi_dsi_bridge_mode_set, --=20 2.41.0