From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793977925; b=xX3hV3E9X5EE+pv7ox8CMaHu/hS6K7fikKcRc+TelN3/NR5mlufZhJ7C60McEx2gl6su GGsXayvlhLFyF0So4AumvZB0S/gt+ZQdLGbmN0Fz89ffhbj67PB85MeODmYbOGv6dyU4H T7sEKWScLYXBIjEXk+WWRIPyvRVVEpI1GO1PZz++RHSVkWmLqnVnXYWf8N+47Fd+HN9nn qBbDmO0BhJDOl9TQVCeA85zTd1eDvX1cVG0oTnTCqt6ZkmReJSRFIHp3Y7mbYAdXyK4mE mjhqKK6VU71tDXjsRboPWyjsew/yy6noYaeofPaoReo28GQYwRKWik29A7dD0NUP0uA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793977925; h=Received:DKIM-Signature:From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:References:In-Reply-To:To:Cc: X-Mailer:X-Developer-Signature:X-Developer-Key; bh=3jowohKTn6iSs9+L8WpiJOpweENgAVcBfJEpPbK3r0g=; b=2Zdoc5wClWZpo+aNOlsEpcOgJDiJR5bIVsEJ9+WgU8P3Ced5Xsp8vaUpFGGnJC7zLAaI yp+k+QfFT3oxHTJ/zqlVgBabDGCdnclTTUzoIx5t3jklI0rasTeQ2VxxUA7ONFbENkiXp Y2L8N4tyr37Y5/e/gXopaEhqYJN1shLuWPp/sBsV4yoo/LTRUhsIsQW9QGBbxT6mcJN4H /STGhv3E3c+MXYfGdPeZ04OapjaVwCPiGgmShJl2LjQUDo8pddLiZdc9hJDw5kSaK9Jt1 GKockN2jwkX/ozDa3N0zBVpV/oU++AHX5bZRTYuKkVobodMuzticOY1ZQcRQEiYLnIg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=HpB41sjs; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EEF22606A32C for ; Fri, 6 Nov 2026 15:12:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=HpB41sjs Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1671A1F008A2; Fri, 6 Nov 2026 15:12:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793977924; bh=3jowohKTn6iSs9+L8WpiJOpweENgAVcBfJEpPbK3r0g=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=HpB41sjsa9w92iBlm2Hm2iU7xoXdYIcq6gaQp+aamy0r5in7fREMw+KtuC6pJinYZ lRIjJXAR00cTMGWcigt2zvSvU912NMaRjP9Q7CjtSSTejcJU7RCrK7KJYJVBgsLsEZ 6xV4B+bKY3jS/+4QbG0llpWgcRypRDxx9rOHshX2qQd8ZLKS/19DzL/WxIntexbkKa nbgQlbafWLNOrjFQG4As2rLhG/wW7CIyUZg35JhtMBVZVjJGv06/ow96JlD8KcXXEr 9xFNqdofALRlF2h7SNqf0eY3r6r6KMR9Fl+zltKEwXYWonDW8QqXT6TNCRv2IJZcA/ 6lAf+dvd/XZew== From: Maxime Ripard Date: Fri, 06 Nov 2026 16:11:42 +0100 Subject: [PATCH v8 4/7] drm/atomic: Allow filling a commit with pristine object states X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261106-drm-reset-state-flag-v8-4-50fd046b705f@kernel.org> References: <20261106-drm-reset-state-flag-v8-0-50fd046b705f@kernel.org> In-Reply-To: <20261106-drm-reset-state-flag-v8-0-50fd046b705f@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=14833; i=mripard@kernel.org; h=from:subject:message-id; bh=+eduEnbYuCQkCBdt0DOJE1krmexUU4BA0AA0iRAQAfk=; b=owGbwMvMwCmsHn9OcpHtvjLG02pJDFlv3xl88J8eOL1T1OHAqc/W1V4MmdKLJc/8rdm1bcoC4 1LrjutFHVNZGIQ5GWTFFFmeyISdXt6+uMrBfuUPmDmsTCBDGLg4BWAii/Yy1kq6Zrw5KSvty2nb zig/v359ndqDVy+4FogvCWe6pn62q6vAdqVdYpOd8nQ1zpdz22W+MTb0vNu+w+y0+a/dMvlK7v6 c959Zvw40fzHzbUG4YCqbZOSiayZJK64oeV135BH79GECwwEA X-Developer-Key: i=mripard@kernel.org; a=openpgp; fpr=BE5675C37E818C8B5764241C254BCFC56BF6CE8D The upcoming DRM_MODE_ATOMIC_RESET flag will need to create an atomic commit that brings the entire device back to a pristine state, as if no configuration had ever been applied. Create drm_atomic_commit_fill_with_defaults() which iterates over all CRTCs, planes, connectors, and color operations in the device and inserts a fresh default state for each one into the commit. This uses the atomic_create_state() hooks rather than atomic_duplicate_state(), since atomic_create_state() provides exactly this pristine state on a per-object basis. Signed-off-by: Maxime Ripard --- drivers/gpu/drm/drm_atomic.c | 355 +++++++++++++++++++++++++++++++++++++++++++ include/drm/drm_atomic.h | 2 + 2 files changed, 357 insertions(+) diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index 7a77051096c9..8bda2871f394 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -1650,4 +1650,359 @@ bool drm_atomic_implements_create_state(struct drm_device *dev) EXPORT_SYMBOL(drm_atomic_implements_create_state); +/* + * Returns true if the colorop state @new differs from the colorop state + * @old. + */ +static bool drm_atomic_colorop_state_changed(const struct drm_colorop_state *old, + const struct drm_colorop_state *new) +{ + return old->bypass != new->bypass || + old->curve_1d_type != new->curve_1d_type || + old->multiplier != new->multiplier || + old->data != new->data || + old->lut1d_interpolation != new->lut1d_interpolation || + old->lut3d_interpolation != new->lut3d_interpolation || + old->fixed_matrix_type != new->fixed_matrix_type; +} + +static int drm_atomic_commit_fill_connector_with_defaults(struct drm_file *file_priv, + struct drm_atomic_commit *commit, + struct drm_connector *connector) +{ + struct drm_connector_state *connector_state; + struct drm_crtc_state *crtc_state; + int ret; + + if (drm_lease_held(file_priv, connector->base.id)) { + /* + * The connector is part of the lease, so it gets a + * pristine state: every property userspace can set goes + * back to its default value, which leaves the connector + * unbound from whatever CRTC it is currently on. + * + * That CRTC still needs to be part of the commit for the + * helpers to update the routing, whether it is leased or + * not, which is what the end of this branch takes care of. + */ + + /* + * drm_atomic_implements_create_state() already checked + * this, but connectors can be hotplugged between that + * lockless check and the iteration here. + */ + if (!connector->funcs->atomic_create_state) + return -EOPNOTSUPP; + + connector_state = connector->funcs->atomic_create_state(connector); + if (IS_ERR(connector_state)) + return PTR_ERR(connector_state); + + /* + * best_encoder is a routing information maintained by the + * atomic helpers rather than a userspace property, and it + * is only carried over to a new state when that state is a + * duplicate of the current one. Since + * update_connector_routing() uses it to detect the commits + * that keep the connector routing unchanged, let's carry + * the encoder currently in use over so that a reset on + * which userspace re-applies the exact same configuration + * doesn't require a modeset. + */ + connector_state->best_encoder = connector->state->best_encoder; + + ret = drm_atomic_commit_set_connector_state(commit, connector, connector_state); + if (ret) { + connector->funcs->atomic_destroy_state(connector, connector_state); + return ret; + } + + if (!connector->state->crtc) + return 0; + + /* + * Make sure the CRTC the connector is currently bound to + * is part of the commit. The atomic helpers need that + * state: set_best_encoder() clears the encoder mask of + * that CRTC when the connector gets detached from it. + */ + crtc_state = drm_atomic_get_crtc_state(commit, + connector->state->crtc); + if (IS_ERR(crtc_state)) + return PTR_ERR(crtc_state); + + /* + * The pristine state unbinds the connector from that + * CRTC, so drop it from the connector mask like + * drm_atomic_set_crtc_for_connector() would. + */ + crtc_state->connector_mask &= ~drm_connector_mask(connector); + } else { + /* + * The connector isn't part of the lease so it keeps its + * current state. If it is bound to a leased CRTC though, + * that CRTC is being reset under it and comes with an + * empty connector mask, so + * drm_atomic_add_affected_connectors() won't find the + * connector during the check. Pull it in here so that its + * routing and encoder are properly handled. + * + * The leased CRTCs are all part of the commit by now. An + * unleased one might not be yet, but it keeps its + * connector mask, so the helpers will pull the connector + * in on their own if that CRTC ends up being changed. + */ + if (!connector->state->crtc) + return 0; + + if (!drm_atomic_get_new_crtc_state(commit, + connector->state->crtc)) + return 0; + + connector_state = drm_atomic_get_connector_state(commit, + connector); + if (IS_ERR(connector_state)) + return PTR_ERR(connector_state); + } + + return 0; +} + +/** + * drm_atomic_commit_fill_with_defaults - populate a commit with pristine states + * @file_priv: DRM file the reset was requested from, or NULL + * @commit: atomic commit to fill + * + * Iterate over all CRTCs, planes, connectors, and color operations in + * the device and insert a freshly created default state for each one + * into @commit. The states are created through the atomic_create_state() + * hooks, producing the same initial state the driver starts with rather + * than a copy of the current hardware state. + * + * If @file_priv is a lessee, only the CRTCs, planes and connectors part + * of its lease are reset, and the other ones are left untouched. + * @file_priv is optional: if NULL, it is considered to not hold any + * lease, and all objects are reset. + * + * The objects that are bound to the objects being reset are still added + * to the commit, with their current state: the CRTC a reset plane or + * connector is bound to, and the connectors bound to a reset CRTC. The + * atomic helpers require them to be part of the commit to update the + * CRTC state and the routing, and they would dereference a NULL state + * otherwise. + * + * In the default state, all objects are disabled: CRTCs are inactive, + * planes are disabled, and connectors are unbound. Driver-specific + * properties such as color pipeline settings or max_bpc may carry + * non-zero defaults appropriate for basic display output. + * + * The CRTC and plane states in the commit carry color_mgmt_changed set + * when the reset changes the color management properties compared to the + * current state, so that drivers reprogram the color management + * hardware. + * + * The connector states keep the encoder currently in use in their + * best_encoder field, like a duplicated state would, so that the atomic + * helpers can detect the commits that don't change the connector + * routing. + * + * This is meant to be used with the %DRM_MODE_ATOMIC_RESET flag, which + * needs to bring the device back to a known baseline before applying + * userspace property changes on top. + * + * Returns: + * 0 on success, or a negative error code on failure. + */ +int drm_atomic_commit_fill_with_defaults(struct drm_file *file_priv, + struct drm_atomic_commit *commit) +{ + struct drm_device *dev = commit->dev; + struct drm_mode_config *config = &dev->mode_config; + struct drm_crtc *crtc; + struct drm_plane *plane; + struct drm_connector *connector; + struct drm_connector_list_iter conn_iter; + struct drm_colorop *colorop; + int ret; + + drm_WARN_ON(dev, !commit->acquire_ctx); + + /* + * Private objects are ignored because none have userspace + * properties we might want to reset. atomic_check + * implementations will derive or infer their private obj state + * from the state that will end up being committed anyway. + * + * The CRTCs are handled before the planes and connectors so that, + * when those pull the CRTC they are currently bound to into the + * commit, a leased CRTC is already there with its pristine state + * while an unleased one gets duplicated and keeps its current + * state. + */ + drm_for_each_crtc(crtc, dev) { + struct drm_crtc_state *crtc_state; + + if (!drm_lease_held(file_priv, crtc->base.id)) + continue; + + ret = drm_modeset_lock(&crtc->mutex, commit->acquire_ctx); + if (ret) + return ret; + + crtc_state = crtc->funcs->atomic_create_state(crtc); + if (IS_ERR(crtc_state)) + return PTR_ERR(crtc_state); + + /* + * The userspace property handlers only set + * color_mgmt_changed when a property write changes the + * value stored in the new state. Since the pristine states + * we create here are already set to their default values, + * restoring those defaults wouldn't set the flag, and + * neither would leaving the properties untouched, even + * though the commit clears whatever LUT or CTM is + * currently programmed. Compare with the current state + * so that the drivers reprogram the color management + * hardware. + */ + crtc_state->color_mgmt_changed = + crtc->state->degamma_lut != crtc_state->degamma_lut || + crtc->state->ctm != crtc_state->ctm || + crtc->state->gamma_lut != crtc_state->gamma_lut; + + /* + * adjusted_mode is derived from the mode by the atomic + * helpers rather than set by userspace, and mode_fixup() + * only recomputes it when the mode or the connectors + * changed. A duplicated state carries it over, so nothing + * needs to be recomputed when nothing changes, but the + * pristine states we create here would be left with a + * zeroed adjusted_mode on a CRTC that stays enabled across + * the commit. Carry it over too, so that the drivers and + * the vblank timestamping constants keep seeing the + * timings currently programmed. + */ + drm_mode_copy(&crtc_state->adjusted_mode, + &crtc->state->adjusted_mode); + + drm_atomic_commit_set_crtc_state(commit, crtc, crtc_state); + } + + drm_for_each_plane(plane, dev) { + struct drm_plane_state *plane_state; + + if (!drm_lease_held(file_priv, plane->base.id)) + continue; + + ret = drm_modeset_lock(&plane->mutex, commit->acquire_ctx); + if (ret) + return ret; + + /* + * Make sure the CRTC the plane is currently enabled on is + * part of the commit, like drm_atomic_set_crtc_for_plane() + * does when userspace disables a plane. The atomic helpers + * need the CRTC state to update planes_changed and track + * the commit, and would dereference a NULL CRTC state + * otherwise. + */ + if (plane->state->crtc) { + struct drm_crtc_state *crtc_state; + + crtc_state = drm_atomic_get_crtc_state(commit, + plane->state->crtc); + if (IS_ERR(crtc_state)) + return PTR_ERR(crtc_state); + + /* + * The pristine state detaches the plane from that + * CRTC, so drop it from the plane mask like + * drm_atomic_set_crtc_for_plane() would. The mask + * of a leased CRTC is already empty, but an + * unleased one got duplicated and still has the + * plane in it. + */ + crtc_state->plane_mask &= ~drm_plane_mask(plane); + } + + plane_state = plane->funcs->atomic_create_state(plane); + if (IS_ERR(plane_state)) + return PTR_ERR(plane_state); + + /* + * Same thing for the planes: report a color pipeline change + * compared to the current state. + */ + plane_state->color_mgmt_changed = + plane->state->color_pipeline != plane_state->color_pipeline; + + drm_atomic_commit_set_plane_state(commit, plane, plane_state); + } + + drm_for_each_colorop(colorop, dev) { + struct drm_plane_state *plane_state; + struct drm_colorop_state *colorop_state; + + if (!drm_lease_held(file_priv, colorop->plane->base.id)) + continue; + + ret = drm_modeset_lock(&colorop->plane->mutex, commit->acquire_ctx); + if (ret) + return ret; + + colorop_state = drm_atomic_helper_colorop_create_state(colorop); + if (IS_ERR(colorop_state)) + return PTR_ERR(colorop_state); + + drm_atomic_commit_set_colorop_state(commit, colorop, colorop_state); + + /* + * Report the colorop state changes on their plane state, + * like drm_atomic_set_property() does when userspace + * changes a colorop property. + */ + if (drm_atomic_colorop_state_changed(colorop->state, colorop_state)) { + plane_state = drm_atomic_get_new_plane_state(commit, + colorop->plane); + if (plane_state) + plane_state->color_mgmt_changed = true; + } + } + + ret = drm_modeset_lock(&config->connection_mutex, commit->acquire_ctx); + if (ret) + return ret; + + drm_connector_list_iter_begin(dev, &conn_iter); + drm_for_each_connector_iter(connector, &conn_iter) { + ret = drm_atomic_commit_fill_connector_with_defaults(file_priv, commit, connector); + if (ret) { + drm_connector_list_iter_end(&conn_iter); + return ret; + } + } + drm_connector_list_iter_end(&conn_iter); + + /* + * drm_lease_held() is evaluated once per object and takes + * idr_mutex each time, so a revocation can land between two of + * those checks and leave the commit with pristine states for some + * objects and the current state for the others. Holding idr_mutex + * across the whole function isn't an option, since + * __drm_mode_object_find() takes it while the modeset locks are + * already held and the ordering is therefore the other way + * around. + * + * A lease is always revoked as a whole though, so the lease + * having gone empty is enough to tell that it didn't survive. + */ + if (drm_lease_revoked(file_priv)) { + drm_dbg_atomic(dev, "Lease revoked while filling the commit\n"); + return -ENOENT; + } + + return 0; +} +EXPORT_SYMBOL(drm_atomic_commit_fill_with_defaults); + /** * drm_atomic_add_encoder_bridges - add bridges attached to an encoder diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h index 72c3d420f40c..cac74d43a34d 100644 --- a/include/drm/drm_atomic.h +++ b/include/drm/drm_atomic.h @@ -704,4 +704,6 @@ void drm_atomic_commit_clear(struct drm_atomic_commit *state); bool drm_atomic_implements_create_state(struct drm_device *dev); +int drm_atomic_commit_fill_with_defaults(struct drm_file *file_priv, + struct drm_atomic_commit *commit); /** -- 2.55.0