From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6497737AA79 for ; Thu, 23 Apr 2026 10:18:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776939511; cv=none; b=SLnKzy65jZ7jVnzdFbkF5Q9/fXUHkk8TK94yI/rfLNjb2Llq4CcytffiTyQwD3JEJjb3DX833KAJZCK6r90SuT2OH1sH2cyGK7vgdBoybdEvAeyqnGhbqUWsFsxmsrriMyInvOHWGo9f3mmlAJe3VC7m8GEMrJ0HjouAu3+05W8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776939511; c=relaxed/simple; bh=QXWXZQEXsf4MFpPvgRFfqvij9UUVaI2oohuViiAF3Gk=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=XmrF7NXgPgVvosyV1fPIW9ry9wd31Tjp6Uviukv4t1iv9EVjoHRdgt1TSa32mqdEfNXKAyWetxjXWaDmm6dR34bJpohaR1oSMsejcNL2pGYj2721MjvJ2EDdt5QLpAZx2g57mJYj1guFKh4m9m0m+5sJwMq0LllCBIQQlvx5PPQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RMr1IdTf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="RMr1IdTf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5BBEC2BCAF; Thu, 23 Apr 2026 10:18:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776939511; bh=QXWXZQEXsf4MFpPvgRFfqvij9UUVaI2oohuViiAF3Gk=; h=From:Subject:Date:To:Cc:From; b=RMr1IdTf/98WrTIUBNX8XGw0uYC7FvTbKaJoOiX29drR4Nju6ig6zfXh0fig+c9bO Uzx6JFS40KdiQ14b4htmUID/lA0Lh3Arbplr/ue2LaZgy390NUHGgE9wxXKvXXEHJl coivkj3e0s/yDTDHNgqc0jgNW9Ky8t2gn9iOfrlB4qH4Thg6D+GwX4yXEXFnlRJzXm elyEjfSj8LD8Sn0/YRv6X/0D37JSIq3OoU8MuQvOfvnXqZUfWwh5Dz0uoAtE0w1djU zEcI3CA8/yY/Av7WHqvoZgkDZuD7v7qfQhDv702xXNrfNvOkbr0oosn5fSkhN512Kb ttl3Sv/D+fCbA== From: Maxime Ripard Subject: [PATCH v2 00/28] drm: Implement state readout support Date: Thu, 23 Apr 2026 12:18:13 +0200 Message-Id: <20260423-drm-state-readout-v2-0-8549f87cb978@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIAAAAAAAC/22PwW7DIBBEf8Xi3K0WME3iU/+jyoHA2lm1hhSIl SryvxfjQy89rWY180bzFJkSUxZD9xSJFs4cQxXqpRPuasNEwL5qoVAZPGgEn2bIxRaCRNbHewG JxxGPJyedRlFzt0QjPxrz47zrRN/3ii77849ci1C9oZY7d46ewMUw8gQcuKJJjkZdDr3xOCxqo 19s3jzzzGXoWoizg0CPAhsLsK9XbL1XziWmnzZtka24rTih+mfFIgFB9tYbLY23enz/pBTo6zW mSZzXdf0FtpnJ6CsBAAA= X-Change-ID: 20250730-drm-state-readout-108f089c1c30 To: Maarten Lankhorst , Thomas Zimmermann , David Airlie , Simona Vetter , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Jyri Sarha , Tomi Valkeinen Cc: Devarsh Thakkar , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Maxime Ripard , Laurent Pinchart X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=8295; i=mripard@kernel.org; h=from:subject:message-id; bh=QXWXZQEXsf4MFpPvgRFfqvij9UUVaI2oohuViiAF3Gk=; b=owGbwMvMwCmsHn9OcpHtvjLG02pJDJkvPz4v6p+lXFCQUvBaRpDrrfp9kZZJU7iEr/EZzYjwv zW1sfJgx1QWBmFOBlkxRZYnMmGnl7cvrnKwX/kDZg4rE8gQBi5OAZiIgQ9jfXJG9l4FT62jpV6M W6vqIj7LOB29oP4gsotBRdFSI3v1xmW80uu3CZWnVp1zlP6y1vUXY8MRq7mTpi22zXWZcy0kZU+ D1eOQRyE37K40/hHpm6z75EpQsNuUto4XXhKHAz+sKDw6TwsA X-Developer-Key: i=mripard@kernel.org; a=openpgp; fpr=BE5675C37E818C8B5764241C254BCFC56BF6CE8D Hi, Here's a series that implement what i915 calls "fastboot", ie, initializing the initial KMS state from the hardware state at boot, to skip the first modeset if the firmware already set up the display. This series creates the infrastructure in KMS to create that state by relying on driver specific hooks. It also implements some infrastructure to check during non-blocking commits that the readout helpers work properly by reading out the state that was just committed and comparing it to what was supposed to be commited. This relies on another set of driver hooks to compare the entities states, with helpers providing the default implementation. It then implements the readout support in the TIDSS driver, and was tested with the SK-AM62 board. This board in particular is pretty interesting, since it relies on an DPI to HDMI bridge, and uses the drm_bridge_connector infrastructure. So the readout works with the current state of the art on embedded-ish It's now in a much better state than the v1 was, but there's still some notable things broken: - Bridges do not read their input and output bus formats and flags - The tidss_crtc_state fields are not read properly at the moment either. - It looks like, when left unattended, we get some atomic_flush WARN eventually, maybe because of something broken around hotplugging and the monitor shutting itself down? - If readout is disabled for any reason, the hardware isn't reset anymore. The main thing works though: the state is picked up properly, doesn't trigger a modeset if what was programmed is the one the first modeset tries to pick as well, will switch properly if it isn't, etc. Let me know what you think, Maxime Signed-off-by: Maxime Ripard --- Changes in v2: - Get rid of patches already applied - Rebase on top of the current atomic_create_state work - Use the SRO prefix everywhere - Create our own states container structure instead of trying to plumb it into a drm_atomic_state - Make a lot more use of helpers - Add a hook to enable the hardware resources when the readout state becomes active - Move all the tidss readout code into tidss_dispc.c - Write documentation - Add drm_private_obj and drm_bridge name for easier debugging - Add drm_private_obj_is_bridge() - Link to v1: https://lore.kernel.org/r/20250902-drm-state-readout-v1-0-14ad5315da3f@kernel.org --- Maxime Ripard (28): drm/atomic: Fix unused but set warning in state iterator macros drm/atomic_helper: Skip over NULL private_obj pointers drm/atomic_state_helper: Remove memset in __drm_atomic_helper_bridge_reset() drm/atomic: Convert drm_priv_to_bridge_state to container_of_const drm/atomic: Add drm_private_obj name drm/bridge: Add drm_private_obj_is_bridge() drm/bridge: Implement atomic_print_state drm/atomic: Export drm_atomic_*_print_state drm/atomic: Only call atomic_destroy_state on a !NULL pointer drm/atomic_sro: Create drm_atomic_sro_state container drm/atomic_sro: Create kernel parameter to force or disable readout drm/atomic_sro: Add atomic state readout infrastructure drm/atomic_sro: Add function to install state into drm objects drm/atomic_sro: Create documentation drm/bridge: Handle bridges with hardware state readout drm/mode_config: Read out hardware state in drm_mode_config_create_state drm/atomic_sro: Provide helpers to implement hardware state readout drm/atomic_helper: Pass nonblock to commit_tail drm/atomic_helper: Compare actual and readout states once the commit is done drm/atomic_state_helper: Provide comparison macros drm/atomic_state_helper: Provide atomic_compare_state helpers drm/encoder: Create atomic_sro_get_current_crtc hook drm/bridge: display-connector: Implement readout support drm/bridge_connector: Implement hw readout for connector drm/tidss: dispc: Improve mode checking logs drm/tidss: Implement readout support drm/tidss: encoder: Implement atomic_sro_get_current_crtc drm/bridge: sii902x: Implement hw state readout drivers/gpu/drm/Makefile | 2 + drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 1 + .../drm/arm/display/komeda/komeda_private_obj.c | 8 + drivers/gpu/drm/bridge/display-connector.c | 15 + drivers/gpu/drm/bridge/sii902x.c | 56 +- drivers/gpu/drm/display/drm_bridge_connector.c | 31 + drivers/gpu/drm/display/drm_dp_mst_topology.c | 2 +- drivers/gpu/drm/display/drm_dp_tunnel.c | 1 + drivers/gpu/drm/drm_atomic.c | 46 +- drivers/gpu/drm/drm_atomic_helper.c | 46 +- drivers/gpu/drm/drm_atomic_sro.c | 854 +++++++++++++++++++++ drivers/gpu/drm/drm_atomic_sro_helper.c | 677 ++++++++++++++++ drivers/gpu/drm/drm_atomic_state_helper.c | 3 +- drivers/gpu/drm/drm_bridge.c | 133 +++- drivers/gpu/drm/drm_internal.h | 12 + drivers/gpu/drm/drm_mode_config.c | 5 + drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 1 + drivers/gpu/drm/ingenic/ingenic-ipu.c | 1 + drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 1 + drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c | 1 + drivers/gpu/drm/omapdrm/omap_drv.c | 1 + drivers/gpu/drm/tegra/hub.c | 1 + drivers/gpu/drm/tidss/tidss_crtc.c | 93 +++ drivers/gpu/drm/tidss/tidss_dispc.c | 332 ++++++-- drivers/gpu/drm/tidss/tidss_dispc.h | 14 + drivers/gpu/drm/tidss/tidss_encoder.c | 37 +- drivers/gpu/drm/tidss/tidss_kms.c | 6 +- drivers/gpu/drm/tidss/tidss_plane.c | 154 ++++ drivers/gpu/drm/vc4/vc4_kms.c | 3 + include/drm/drm_atomic.h | 144 +++- include/drm/drm_atomic_sro.h | 59 ++ include/drm/drm_atomic_sro_helper.h | 275 +++++++ include/drm/drm_bridge.h | 87 +++ include/drm/drm_connector.h | 69 ++ include/drm/drm_crtc.h | 69 ++ include/drm/drm_encoder.h | 18 + include/drm/drm_mode_config.h | 18 + include/drm/drm_modeset_helper_vtables.h | 23 + include/drm/drm_plane.h | 69 ++ 39 files changed, 3255 insertions(+), 113 deletions(-) --- base-commit: ea61048876a7137897da26dac49ee234fb38a35a change-id: 20250730-drm-state-readout-108f089c1c30 prerequisite-change-id: 20260310-drm-mode-config-init-1e1f52b745d0:v2 prerequisite-patch-id: 8831e320ca55e930e6dd8db8abfd2a79179fc1a0 prerequisite-patch-id: 5d2ae478dfb0a8b1eed30431b52a63141f1a3edb prerequisite-patch-id: be3ef2f85cc3bba3ce65cbe4c1bf73b26c59b46c prerequisite-patch-id: ad4de3b4f7bf5861d8e74d15042fb1d17cf6f071 prerequisite-patch-id: 6af92ef1aef1541ba0c504c3618612a89f5433a4 prerequisite-patch-id: d7b9200d7155e7ae2a76121adb50ce974aa78ddc prerequisite-patch-id: 811a936fa6b38549807256e718b4c1faf49e90dd prerequisite-patch-id: 3816a4bdc28e3353dba2811cc82d6680cf9ada11 prerequisite-patch-id: e156096dae812cab909877d7d614f56374652c6a prerequisite-patch-id: fa0187e85c3587e7b28e411f2198b7c070793fbb prerequisite-patch-id: f97b4088a1357121e4b35c4822839e45d952cba9 prerequisite-patch-id: 2e942d5540fc208b0c94f9f9215f85cc59dd6c1c prerequisite-patch-id: 45ce20ef439a538b6c71c7aedb251bd62c882a11 prerequisite-patch-id: 86674e487ba650461e29c284308ff9ba321a48e4 prerequisite-patch-id: 1d7744840555f74f310c1d48642bfc755ac645c9 prerequisite-patch-id: b01716030f5f9b3cedb4a6096b2d4769f625741a prerequisite-patch-id: 0372103622aa6006a3fe645b4c2eb2387d7d3b5a prerequisite-patch-id: 24a0b772f6fc53c41892a37b52cba95bbd261ca2 prerequisite-patch-id: 80ec7eea600ad3be7b94a182e274695b7c5cf17f prerequisite-patch-id: 273773ea001ab348b4e85b47b20b45f48d4c1cbc Best regards, -- Maxime Ripard