From nobody Sun Sep 22 09:30:44 2024 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 81F70C433EF for ; Thu, 27 Jan 2022 14:36:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242449AbiA0Ogd (ORCPT ); Thu, 27 Jan 2022 09:36:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242420AbiA0Ogc (ORCPT ); Thu, 27 Jan 2022 09:36:32 -0500 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69427C061714 for ; Thu, 27 Jan 2022 06:36:32 -0800 (PST) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: kholk11) with ESMTPSA id DFA301F45393 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1643294190; bh=3IdE6LoZ1ETmacWuilGWdcqDG0QyqCl29Cn/VqP2g/s=; h=From:To:Cc:Subject:Date:From; b=T595yv6mYzunV8OirmSDlCOEeBshfA/Gcqi6nDLt7C4T1u9Wy2UCurKE7qa2PpN4x fhh3u5klUdom2Q6cVe+7WM8m1D/sPVqxTn/jZB7HSu1uluq/R0KKk4nakG6yoyOp+L dZEesjMmV71Xugvsc2/SXXA5VvVr4k1sC4pvulSP7R7a5ZpMcYW/XLsWcbYNNHpcCE VbkjoABbxwfDsVcgLReyjO7Y1U5eU2UFiKS51RSqLtyVPlLiaQEvIENc/kaQzAWQSG GbTJr6GOb7/wuJYdhVWAykUyAveX1XTmIZ/eMhQPyoKStO1+oFonBxnmLg3FzsHc5/ 22jZxZ+cmucXQ== From: AngeloGioacchino Del Regno To: dri-devel@lists.freedesktop.org Cc: linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, chunkuang.hu@kernel.org, p.zabel@pengutronix.de, airlied@linux.ie, daniel@ffwll.ch, matthias.bgg@gmail.com, kernel@collabora.com, andrzej.hajda@intel.com, AngeloGioacchino Del Regno , Jagan Teki Subject: [PATCH v3] drm/mediatek: mtk_dsi: Avoid EPROBE_DEFER loop with external bridge Date: Thu, 27 Jan 2022 15:36:23 +0100 Message-Id: <20220127143623.123025-1-angelogioacchino.delregno@collabora.com> X-Mailer: git-send-email 2.33.1 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" DRM bridge drivers are now attaching their DSI device at probe time, which requires us to register our DSI host in order to let the bridge to probe: this recently started producing an endless -EPROBE_DEFER loop on some machines that are using external bridges, like the parade-ps8640, found on the ACER Chromebook R13. Now that the DSI hosts/devices probe sequence is documented, we can do adjustments to the mtk_dsi driver as to both fix now and make sure to avoid this situation in the future: for this, following what is documented in drm_bridge.c, move the mtk_dsi component_add() to the mtk_dsi_ops.attach callback and delete it in the detach callback; keeping in mind that we are registering a drm_bridge for our DSI, which is only used/attached if the DSI Host is bound, it wouldn't make sense to keep adding our bridge at probe time (as it would be useless to have it if mtk_dsi_ops.attach() fails!), so also move that one to the dsi host attach function (and remove it in detach). Fixes: 209264a85707 ("drm/bridge: Document the probe issue with MIPI-DSI br= idges") Signed-off-by: AngeloGioacchino Del Regno Reviewed-by: Andrzej Hajda Reviewed-by: Jagan Teki --- drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++-------------- 1 file changed, 84 insertions(+), 83 deletions(-) diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/= mtk_dsi.c index 5d90d2eb0019..bced4c7d668e 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev) mtk_dsi_poweroff(dsi); } =20 +static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *ds= i) +{ + int ret; + + ret =3D drm_simple_encoder_init(drm, &dsi->encoder, + DRM_MODE_ENCODER_DSI); + if (ret) { + DRM_ERROR("Failed to encoder init to drm\n"); + return ret; + } + + dsi->encoder.possible_crtcs =3D mtk_drm_find_possible_crtc_by_comp(drm, d= si->host.dev); + + ret =3D drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, + DRM_BRIDGE_ATTACH_NO_CONNECTOR); + if (ret) + goto err_cleanup_encoder; + + dsi->connector =3D drm_bridge_connector_init(drm, &dsi->encoder); + if (IS_ERR(dsi->connector)) { + DRM_ERROR("Unable to create bridge connector\n"); + ret =3D PTR_ERR(dsi->connector); + goto err_cleanup_encoder; + } + drm_connector_attach_encoder(dsi->connector, &dsi->encoder); + + return 0; + +err_cleanup_encoder: + drm_encoder_cleanup(&dsi->encoder); + return ret; +} + +static int mtk_dsi_bind(struct device *dev, struct device *master, void *d= ata) +{ + int ret; + struct drm_device *drm =3D data; + struct mtk_dsi *dsi =3D dev_get_drvdata(dev); + + ret =3D mtk_dsi_encoder_init(drm, dsi); + if (ret) + return ret; + + return device_reset_optional(dev); +} + +static void mtk_dsi_unbind(struct device *dev, struct device *master, + void *data) +{ + struct mtk_dsi *dsi =3D dev_get_drvdata(dev); + + drm_encoder_cleanup(&dsi->encoder); +} + +static const struct component_ops mtk_dsi_component_ops =3D { + .bind =3D mtk_dsi_bind, + .unbind =3D mtk_dsi_unbind, +}; + static int mtk_dsi_host_attach(struct mipi_dsi_host *host, struct mipi_dsi_device *device) { struct mtk_dsi *dsi =3D host_to_dsi(host); + struct device *dev =3D host->dev; + int ret; =20 dsi->lanes =3D device->lanes; dsi->format =3D device->format; dsi->mode_flags =3D device->mode_flags; + dsi->next_bridge =3D devm_drm_of_get_bridge(dev, dev->of_node, 0, 0); + if (IS_ERR(dsi->next_bridge)) + return PTR_ERR(dsi->next_bridge); + + drm_bridge_add(&dsi->bridge); + + ret =3D component_add(host->dev, &mtk_dsi_component_ops); + if (ret) { + DRM_ERROR("failed to add dsi_host component: %d\n", ret); + drm_bridge_remove(&dsi->bridge); + return ret; + } =20 return 0; } =20 +static int mtk_dsi_host_detach(struct mipi_dsi_host *host, + struct mipi_dsi_device *device) +{ + struct mtk_dsi *dsi =3D host_to_dsi(host); + + component_del(host->dev, &mtk_dsi_component_ops); + drm_bridge_remove(&dsi->bridge); + return 0; +} + static void mtk_dsi_wait_for_idle(struct mtk_dsi *dsi) { int ret; @@ -938,73 +1021,14 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi= _host *host, =20 static const struct mipi_dsi_host_ops mtk_dsi_ops =3D { .attach =3D mtk_dsi_host_attach, + .detach =3D mtk_dsi_host_detach, .transfer =3D mtk_dsi_host_transfer, }; =20 -static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *ds= i) -{ - int ret; - - ret =3D drm_simple_encoder_init(drm, &dsi->encoder, - DRM_MODE_ENCODER_DSI); - if (ret) { - DRM_ERROR("Failed to encoder init to drm\n"); - return ret; - } - - dsi->encoder.possible_crtcs =3D mtk_drm_find_possible_crtc_by_comp(drm, d= si->host.dev); - - ret =3D drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, - DRM_BRIDGE_ATTACH_NO_CONNECTOR); - if (ret) - goto err_cleanup_encoder; - - dsi->connector =3D drm_bridge_connector_init(drm, &dsi->encoder); - if (IS_ERR(dsi->connector)) { - DRM_ERROR("Unable to create bridge connector\n"); - ret =3D PTR_ERR(dsi->connector); - goto err_cleanup_encoder; - } - drm_connector_attach_encoder(dsi->connector, &dsi->encoder); - - return 0; - -err_cleanup_encoder: - drm_encoder_cleanup(&dsi->encoder); - return ret; -} - -static int mtk_dsi_bind(struct device *dev, struct device *master, void *d= ata) -{ - int ret; - struct drm_device *drm =3D data; - struct mtk_dsi *dsi =3D dev_get_drvdata(dev); - - ret =3D mtk_dsi_encoder_init(drm, dsi); - if (ret) - return ret; - - return device_reset_optional(dev); -} - -static void mtk_dsi_unbind(struct device *dev, struct device *master, - void *data) -{ - struct mtk_dsi *dsi =3D dev_get_drvdata(dev); - - drm_encoder_cleanup(&dsi->encoder); -} - -static const struct component_ops mtk_dsi_component_ops =3D { - .bind =3D mtk_dsi_bind, - .unbind =3D mtk_dsi_unbind, -}; - static int mtk_dsi_probe(struct platform_device *pdev) { struct mtk_dsi *dsi; struct device *dev =3D &pdev->dev; - struct drm_panel *panel; struct resource *regs; int irq_num; int ret; @@ -1021,19 +1045,6 @@ static int mtk_dsi_probe(struct platform_device *pde= v) return ret; } =20 - ret =3D drm_of_find_panel_or_bridge(dev->of_node, 0, 0, - &panel, &dsi->next_bridge); - if (ret) - goto err_unregister_host; - - if (panel) { - dsi->next_bridge =3D devm_drm_panel_bridge_add(dev, panel); - if (IS_ERR(dsi->next_bridge)) { - ret =3D PTR_ERR(dsi->next_bridge); - goto err_unregister_host; - } - } - dsi->driver_data =3D of_device_get_match_data(dev); =20 dsi->engine_clk =3D devm_clk_get(dev, "engine"); @@ -1098,14 +1109,6 @@ static int mtk_dsi_probe(struct platform_device *pde= v) dsi->bridge.of_node =3D dev->of_node; dsi->bridge.type =3D DRM_MODE_CONNECTOR_DSI; =20 - drm_bridge_add(&dsi->bridge); - - ret =3D component_add(&pdev->dev, &mtk_dsi_component_ops); - if (ret) { - dev_err(&pdev->dev, "failed to add component: %d\n", ret); - goto err_unregister_host; - } - return 0; =20 err_unregister_host: @@ -1118,8 +1121,6 @@ static int mtk_dsi_remove(struct platform_device *pde= v) struct mtk_dsi *dsi =3D platform_get_drvdata(pdev); =20 mtk_output_dsi_disable(dsi); - drm_bridge_remove(&dsi->bridge); - component_del(&pdev->dev, &mtk_dsi_component_ops); mipi_dsi_host_unregister(&dsi->host); =20 return 0; --=20 2.33.1