From patchwork Wed Aug 2 07:04:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomi Valkeinen X-Patchwork-Id: 13337726 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E767CC001DF for ; Wed, 2 Aug 2023 07:04:35 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 5067A10E4C3; Wed, 2 Aug 2023 07:04:35 +0000 (UTC) Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0587010E4C3 for ; Wed, 2 Aug 2023 07:04:34 +0000 (UTC) Received: from [127.0.1.1] (91-154-35-171.elisa-laajakaista.fi [91.154.35.171]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id E26A62AC; Wed, 2 Aug 2023 09:03:27 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1690959809; bh=Sc8D2SdGCbu9XTm7K1J4nA4tf4ujy8AiwCNW6zEjPtc=; h=From:Date:Subject:To:Cc:From; b=FfYfM4N1drAfSIeYowE2wcYQqqWWGXUNPsNmJTifGB3F4oblbZ11WejjArS67hcBc SawOP2YSmRBD5TbVXcMYg9rxRf89vRNzIh2J1XMP6ntdz5K2lawkM2n/+wz/Y4gKuV SdNXTwmsjuSnaC8Jvz8V0SOg/Kqf59R9E5NBgd14= From: Tomi Valkeinen Date: Wed, 02 Aug 2023 10:04:11 +0300 Subject: [PATCH v4] drm/bridge: Add debugfs print for bridge chains MIME-Version: 1.0 Message-Id: <20230802-drm-bridge-chain-debugfs-v4-1-7e3ae3d137c0@ideasonboard.com> X-B4-Tracking: v=1; b=H4sIAOr/yWQC/43NwQ6CMAwG4FchOzvDNmDgyfcwHjbaQQ8wsynRE N7dwcmDGo5/+/frzCIGwshO2cwCThTJjykUh4y1vRk75AQpM5lLlWspOISB20CQNqlAIwe0j85 FnlvbilJKV2rD0vktoKPnRl+uKfcU7z68tk+TWKc70ElwwetKFM5prJsczgRooh+tNwGOrR/Ya k9yryeTpytwTaEK3VTyh6c+PPXPU6sHqdQ4hc6oL96yLG8cHJZeZwEAAA== To: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Francesco Dolcini , Aradhya Bhatia , Alexander Stein X-Mailer: b4 0.12.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=5273; i=tomi.valkeinen@ideasonboard.com; h=from:subject:message-id; bh=Sc8D2SdGCbu9XTm7K1J4nA4tf4ujy8AiwCNW6zEjPtc=; b=owEBbQKS/ZANAwAIAfo9qoy8lh71AcsmYgBkyf/+VtvShjhA7H75mV9NW+L+8CI5miTedTfg4 kZX80rCnOqJAjMEAAEIAB0WIQTEOAw+ll79gQef86f6PaqMvJYe9QUCZMn//gAKCRD6PaqMvJYe 9QfpEACrXQFv2Ayfa1k0W/JGf0tSkIMgGLOj+jKErewnpXnU4asuDy7L1nDvLETTeZqewh0kgeI H4GyAQWnfW9ZUz7yT7rde9JuhQ4IQESLEABJIoeGqRrtQkURMhIddpjyRpojImMK8sJIsoL2dOU bVHaPx/iXOMTVYrHPxmxtXkfQFGNi6XCuyR3agRgPbqY5UutHsfs3+buGi3n4A2WvGHHy1Xx2KA LWjmo39BWeME8UdJS8TF4nv8wJmb+gy0qBGgVrNYPzmyyV4Ah8HkK/n9BjBDLxUgfuUTLPZD1q9 HYA2adM4MqIwiVS2I3yoNvsiLHqwJnO93m/5/z6w5sPFTvGv8VpG2BgHmJgRKnF0WM2HfFphl4v 7xVGDWmJ69KIIzAts85OSG73c51uuGWXqlZSZjDmXtx7zulo+atABN5Doua/7UUPqI45RgwuZI6 VhsQwnO9qv0c8JBRK2+bL/SlsVgjNVK1nPrp7IhU+VZQGCTjWe89/U2jlKd9BwWtAzTZk7dRABB 5zY+KZUHcN+p2ip1soeAH3olT7NlvgjGJoMgo3j4CcLElHD1ORR7Whd83zSBEgpvLvibfOHIF7Q gFiiFdbcVvU+en2hxioU9tabXguJ8iXqNQr1ehDp5U+i8VcSq9iwSjSppu1ec6KY1IdK7z4xC3x 3lp923aLWPDC8Fw== X-Developer-Key: i=tomi.valkeinen@ideasonboard.com; a=openpgp; fpr=C4380C3E965EFD81079FF3A7FA3DAA8CBC961EF5 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tomi Valkeinen , Laurent Pinchart , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" DRM bridges are not visible to the userspace and it may not be immediately clear if the chain is somehow constructed incorrectly. I have had two separate instances of a bridge driver failing to do a drm_bridge_attach() call, resulting in the bridge connector not being part of the chain. In some situations this doesn't seem to cause issues, but it will if DRM_BRIDGE_ATTACH_NO_CONNECTOR flag is used. Add a debugfs file to print the bridge chains. For me, on this TI AM62 based platform, I get the following output: encoder[39] bridge[0] type: 0, ops: 0x0 bridge[1] type: 0, ops: 0x0, OF: /bus@f0000/i2c@20000000/dsi@e:toshiba,tc358778 bridge[2] type: 0, ops: 0x3, OF: /bus@f0000/i2c@20010000/hdmi@48:lontium,lt8912b bridge[3] type: 11, ops: 0x7, OF: /hdmi-connector:hdmi-connector Tested-by: Alexander Stein Reviewed-by: Laurent Pinchart Signed-off-by: Tomi Valkeinen Acked-by: Neil Armstrong --- Changes in v4: - Move 'struct drm_minor' to be along the other declarations - Added Tested-by and Reviewed-by - Link to v3: https://lore.kernel.org/r/20230731-drm-bridge-chain-debugfs-v3-1-7d0739f3efa3@ideasonboard.com Changes in v3: - Use drm_for_each_bridge_in_chain() - Drop extra comment - Fix whitespace issue - Call drm_bridge_debugfs_init() only if the driver uses modeset - Drop #ifdef for drm_bridge_debugfs_init() declaration - Link to v2: https://lore.kernel.org/r/20230721-drm-bridge-chain-debugfs-v2-1-76df94347962@ideasonboard.com Changes in v2: - Fixed compilation issue when !CONFIG_OF - Link to v1: https://lore.kernel.org/r/20230721-drm-bridge-chain-debugfs-v1-1-8614ff7e890d@ideasonboard.com --- drivers/gpu/drm/drm_bridge.c | 46 +++++++++++++++++++++++++++++++++++++++++++ drivers/gpu/drm/drm_debugfs.c | 2 ++ include/drm/drm_bridge.h | 3 +++ 3 files changed, 51 insertions(+) --- base-commit: a0c64d153d687756c8719b8d10e609d62e1cb6fd change-id: 20230721-drm-bridge-chain-debugfs-0bbc1522f57a Best regards, diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index c3d69af02e79..39e68e45bb12 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -27,8 +27,10 @@ #include #include +#include #include #include +#include #include #include @@ -1345,6 +1347,50 @@ struct drm_bridge *of_drm_find_bridge(struct device_node *np) EXPORT_SYMBOL(of_drm_find_bridge); #endif +#ifdef CONFIG_DEBUG_FS +static int drm_bridge_chains_info(struct seq_file *m, void *data) +{ + struct drm_debugfs_entry *entry = m->private; + struct drm_device *dev = entry->dev; + struct drm_printer p = drm_seq_file_printer(m); + struct drm_mode_config *config = &dev->mode_config; + struct drm_encoder *encoder; + unsigned int bridge_idx = 0; + + list_for_each_entry(encoder, &config->encoder_list, head) { + struct drm_bridge *bridge; + + drm_printf(&p, "encoder[%u]\n", encoder->base.id); + + drm_for_each_bridge_in_chain(encoder, bridge) { + drm_printf(&p, "\tbridge[%u] type: %u, ops: %#x", + bridge_idx, bridge->type, bridge->ops); + +#ifdef CONFIG_OF + if (bridge->of_node) + drm_printf(&p, ", OF: %pOFfc", bridge->of_node); +#endif + + drm_printf(&p, "\n"); + + bridge_idx++; + } + } + + return 0; +} + +static const struct drm_debugfs_info drm_bridge_debugfs_list[] = { + { "bridge_chains", drm_bridge_chains_info, 0 }, +}; + +void drm_bridge_debugfs_init(struct drm_minor *minor) +{ + drm_debugfs_add_files(minor->dev, drm_bridge_debugfs_list, + ARRAY_SIZE(drm_bridge_debugfs_list)); +} +#endif + MODULE_AUTHOR("Ajay Kumar "); MODULE_DESCRIPTION("DRM bridge infrastructure"); MODULE_LICENSE("GPL and additional rights"); diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c index a3a488205009..2de43ff3ce0a 100644 --- a/drivers/gpu/drm/drm_debugfs.c +++ b/drivers/gpu/drm/drm_debugfs.c @@ -31,6 +31,7 @@ #include #include +#include #include #include #include @@ -274,6 +275,7 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id, if (drm_drv_uses_atomic_modeset(dev)) { drm_atomic_debugfs_init(minor); + drm_bridge_debugfs_init(minor); } if (drm_core_check_feature(dev, DRIVER_MODESET)) { diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index bf964cdfb330..c339fc85fd07 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -36,6 +36,7 @@ struct drm_bridge; struct drm_bridge_timings; struct drm_connector; struct drm_display_info; +struct drm_minor; struct drm_panel; struct edid; struct i2c_adapter; @@ -949,4 +950,6 @@ static inline struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm, } #endif +void drm_bridge_debugfs_init(struct drm_minor *minor); + #endif