From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 11342443E2F for ; Fri, 16 Oct 2026 07:32:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792135967; cv=none; b=nfFr2dKB+hi92xbOCW1f4SWDL0koNLpqhv5k8dlfIgtv6eeeh+K2jzgQ8rDqthOOohNO21ejHBgECf+TremSt+w/gCvZVhxfGEYa5ODVL0oiNcU/GnafVjxdWiVT3kVU6QdGBpFsFHrZCgfsChkp1+re26Fkjw2vFOu8UHgqQoI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792135967; c=relaxed/simple; bh=lSSbo17GwTKi0HPe8dSl3Q7vpbqWzmF8ZCg4N7OVwqc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=gp8SrzzLC4qGDEqaMgh3EIIIHLP2GNPRi6I+HI9yTxi91YLFZLvJsAHnx5F742RMxsv2HdNu49W/hsgIEsStdrKZ1Ku1pLuSx/JqqhfJi0YKg9aG5UUWTSIjgQ3ZivczylDR2r7PyVXSLUlX112o7k8sIXbvN0Z30KYF8SKEcVY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lCTAosZK; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lCTAosZK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3EB461F000C4; Fri, 16 Oct 2026 07:32:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792135966; bh=hJ748OJD4EGGOP8kHF6eaGLRYK9VW49NzKuXO/Q9eUk=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=lCTAosZKSdg049scKKG8AtetjtAIpyzZ6nwZrupbjYxcfOVioq8g38y5aFRulzytn gMUMjoYreNG/LRSImDxpvF1614I0uwtjrmy9yV7gbotFE9+76L45DNzIAxuALZz9BU iIZXq4hpkwcfKT+awvTNgwwKnaGB7HcVh7gCDAtn4NiGlyulaXgtXg141cIAaVDAYv CFwV7gKUQEhp2LljTKw4UPIQOHeGTY38z3uGJAs77yfQfGbtHc+ijai4JtgX4eauvi 2bryf9vJ9tVy2ceTPpn/xpXl4G2J7OFCISgGPoqwqh8C2Tk6DYAcAAxdwmi8/GRmPt MYPFuO0bPH/Ig== From: Maxime Ripard Date: Fri, 16 Oct 2026 09:31:44 +0200 Subject: [PATCH v5 12/14] drm/atomic-uapi: Add DRM_MODE_ATOMIC_RESET flag 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 Message-Id: <20261016-drm-reset-state-flag-v5-12-dad2d64b693b@kernel.org> References: <20261016-drm-reset-state-flag-v5-0-dad2d64b693b@kernel.org> In-Reply-To: <20261016-drm-reset-state-flag-v5-0-dad2d64b693b@kernel.org> To: Maarten Lankhorst , Thomas Zimmermann , David Airlie , Simona Vetter , Louis Chauvet , Haneen Mohammed , Melissa Wen Cc: Daniel Stone , Harry Wentland , Jocelyn Falempe , =?utf-8?q?Jonas_=C3=85dahl?= , =?utf-8?q?Michel_D=C3=A4nzer?= , Pekka Paalanen , Sebastian Wick , Simon Ser , Victoria Brekenfeld , Xaver Hugl , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Maxime Ripard X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=6328; i=mripard@kernel.org; h=from:subject:message-id; bh=YlkfrruRPUUGnfBvwlLBJBqXQf46kNIOtByY30vX/Yk=; b=owGbwMvMwCmsHn9OcpHtvjLG02pJDFkXLz176mXM5Zib/X6H9+H7LU6TBOb8unvp4If5b7f/M F/pODFApWMqC4MwJ4OsmCLLE5mw08vbF1c52K/8ATOHlQlkCAMXpwBM5IoOY8PmZTuYN8bOFzpQ EFN65uBsod9b+arVn014UyCi/+T5SqNrvX4n9kottP7KvTjd8cI97RbGhg8Tr7zvndG9/uzLhkk qQYsr+TJylzI8ceSeUvf+1OIgy30VJ9Nfai+Y9VA7ffvSeW0ptwA= X-Developer-Key: i=mripard@kernel.org; a=openpgp; fpr=BE5675C37E818C8B5764241C254BCFC56BF6CE8D From: Sebastian Wick Userspace currently has no atomic way to reset all KMS object states to their defaults. To bring a display pipeline to a known state, a compositor must explicitly set every property on every object, which requires tracking which properties exist and what their defaults are. Introduce DRM_MODE_ATOMIC_RESET (0x0800) which, when passed to the atomic ioctl, fills the commit with default states for all KMS objects before applying the properties supplied in the request. Properties not explicitly included in the commit remain at their defaults (CRTCs inactive, planes disabled, connectors unbound, and so on). The flag cannot be combined with DRM_MODE_PAGE_FLIP_ASYNC, since a full state reset is incompatible with an async flip. Reviewed-by: Thomas Zimmermann Signed-off-by: Sebastian Wick Co-developed-by: Maxime Ripard Reviewed-by: Daniel Stone Signed-off-by: Maxime Ripard --- drivers/gpu/drm/drm_atomic.c | 3 +++ drivers/gpu/drm/drm_atomic_uapi.c | 18 ++++++++++++++++++ drivers/gpu/drm/drm_ioctl.c | 3 +++ include/uapi/drm/drm.h | 10 ++++++++++ include/uapi/drm/drm_mode.h | 14 +++++++++++++- 5 files changed, 47 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index b65116e97e39..871dbd6eb14a 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -1611,10 +1611,13 @@ EXPORT_SYMBOL(drm_atomic_get_new_bridge_state); * the current state. * * Color operations are not checked because they always use * drm_atomic_helper_colorop_create_state() and do not have a per-driver hook. * + * This is used to report the %DRM_CAP_ATOMIC_RESET capability to userspace, + * and as a precondition in drm_atomic_commit_fill_with_defaults(). + * * Returns: * True if all objects implement atomic_create_state, false otherwise. */ bool drm_atomic_implements_create_state(struct drm_device *dev) { diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c index 1eebcf6f5e05..237c7ff82352 100644 --- a/drivers/gpu/drm/drm_atomic_uapi.c +++ b/drivers/gpu/drm/drm_atomic_uapi.c @@ -1671,10 +1671,17 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, drm_dbg_atomic(dev, "commit failed: page-flip event requested with test-only commit\n"); return -EINVAL; } + if ((arg->flags & DRM_MODE_ATOMIC_RESET) && + (arg->flags & DRM_MODE_PAGE_FLIP_ASYNC)) { + drm_dbg_atomic(dev, + "commit failed: reset cannot be combined with async flip\n"); + return -EINVAL; + } + state = drm_atomic_commit_alloc(dev); if (!state) return -ENOMEM; drm_modeset_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE); @@ -1686,10 +1693,21 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, copied_objs = 0; copied_props = 0; fence_state = NULL; num_fences = 0; + if (arg->flags & DRM_MODE_ATOMIC_RESET) { + if (!drm_atomic_implements_create_state(dev)) { + ret = -EOPNOTSUPP; + goto out; + } + + ret = drm_atomic_commit_fill_with_defaults(state); + if (ret) + goto out; + } + for (i = 0; i < arg->count_objs; i++) { uint32_t obj_id, count_props; struct drm_mode_object *obj; if (get_user(obj_id, objs_ptr + copied_objs)) { diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index 0dbf04d4aa9e..e589d93871e2 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -303,10 +303,13 @@ static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_ break; case DRM_CAP_ATOMIC_ASYNC_PAGE_FLIP: req->value = drm_core_check_feature(dev, DRIVER_ATOMIC) && dev->mode_config.async_page_flip; break; + case DRM_CAP_ATOMIC_RESET: + req->value = drm_atomic_implements_create_state(dev); + break; default: return -EINVAL; } return 0; } diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index bc7ef7684099..b6e2f2edd122 100644 --- a/include/uapi/drm/drm.h +++ b/include/uapi/drm/drm.h @@ -793,10 +793,20 @@ struct drm_gem_change_handle { * If set to 1, the driver supports &DRM_MODE_PAGE_FLIP_ASYNC for atomic * commits. */ #define DRM_CAP_ATOMIC_ASYNC_PAGE_FLIP 0x15 +/** + * DRM_CAP_ATOMIC_RESET + * + * If set to 1, the driver supports the &DRM_MODE_ATOMIC_RESET flag in + * &DRM_IOCTL_MODE_ATOMIC commits. When supported, userspace can pass that + * flag to reset all KMS object states to their defaults before applying + * property changes. + */ +#define DRM_CAP_ATOMIC_RESET 0x16 + /* DRM_IOCTL_GET_CAP ioctl argument type */ struct drm_get_cap { __u64 capability; __u64 value; }; diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h index ed1a660a3dfd..32eb3f650d7a 100644 --- a/include/uapi/drm/drm_mode.h +++ b/include/uapi/drm/drm_mode.h @@ -1326,10 +1326,21 @@ struct drm_mode_destroy_dumb { * To the best of the driver's knowledge, visual artifacts are guaranteed to * not appear when this flag is not set. Some sinks might display visual * artifacts outside of the driver's control. */ #define DRM_MODE_ATOMIC_ALLOW_MODESET 0x0400 +/** + * DRM_MODE_ATOMIC_RESET + * + * Reset all KMS object states (CRTCs, planes, connectors, color operations) + * to their default values before applying the properties in this commit. + * Properties not explicitly included in the commit will remain at their + * defaults (CRTCs inactive, planes disabled, connectors unbound, etc.). + * + * This flag cannot be combined with &DRM_MODE_PAGE_FLIP_ASYNC. + */ +#define DRM_MODE_ATOMIC_RESET 0x0800 /** * DRM_MODE_ATOMIC_FLAGS * * Bitfield of flags accepted by the &DRM_IOCTL_MODE_ATOMIC IOCTL in @@ -1338,11 +1349,12 @@ struct drm_mode_destroy_dumb { #define DRM_MODE_ATOMIC_FLAGS (\ DRM_MODE_PAGE_FLIP_EVENT |\ DRM_MODE_PAGE_FLIP_ASYNC |\ DRM_MODE_ATOMIC_TEST_ONLY |\ DRM_MODE_ATOMIC_NONBLOCK |\ - DRM_MODE_ATOMIC_ALLOW_MODESET) + DRM_MODE_ATOMIC_ALLOW_MODESET |\ + DRM_MODE_ATOMIC_RESET) struct drm_mode_atomic { __u32 flags; __u32 count_objs; __u64 objs_ptr; -- 2.55.0