From nobody Fri Dec 19 21:13:51 2025 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (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 C90D231158A for ; Wed, 3 Dec 2025 18:28:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764786534; cv=none; b=Q/slA/FRCo4ECaFvrjxur5swlwnjyDXhP5uDydS096I5jhV5X8K+OU+j/TH1uwatHtZV6StvxhbFTlJEVKtfS8dM0bN0ioRqWFMPh8lOfdfkmVhuhG+0UbGy20AcQcljMAziG6gLghzTL6CHbVAZZ7UEaNV0uItvjAV7PPKLU7E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764786534; c=relaxed/simple; bh=iYE+4UPkyqxTrSULtDzHdjdb79m0OVRNfhA4Xnqm7pI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=IemGoQIt3S4qba40/cjVEbN6pQi775KOeqBzSQBGn2BAXELGsDdOamLYGemLiCdPv0UWC7UPeo4yF/hkksfNDDrbNUynC7XZpxb8IyxNdNfBZ/NvOFVaic0z4zUOM+QrzT+RJA7xbVKJotOJ/lozRJOKd9EEI4C9Y/TJ9ocKFhI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=S9qLeMGF; arc=none smtp.client-ip=148.251.105.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="S9qLeMGF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1764786530; bh=iYE+4UPkyqxTrSULtDzHdjdb79m0OVRNfhA4Xnqm7pI=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=S9qLeMGFgmxmYmDXTM5boYIUoLs7eWKOW1sh8LOI9SFCUVbPuPxCMLFUNALOYjLw0 +S5KIkF7SvMGz7P2ilri8RwV/wCXibQ6BfEAM0gLlv3OB4acS6LQq+nSjkezs8IYPy F3qZA34v3/mCNiKE9VKBVlcTor7+ePRFYCBaE1MXMoKoA2TrbCjk++8zZxpw7Bi9Xc aUSVmoAEPl0JEE4WC4i4be3yDbeELtez63g/AqXhOqWonzMpgEppXXcwQvhG4sN/We DgsPwb9UAad7Sw/5yc+PCeWQ1zWSukAdAxvaApQWOA/7vFNo+aYScben+6vxx5eGu7 AuFkdNHp04ZwQ== Received: from localhost (unknown [82.79.138.145]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: cristicc) by bali.collaboradmins.com (Postfix) with ESMTPSA id A348517E0360; Wed, 3 Dec 2025 19:28:50 +0100 (CET) From: Cristian Ciocaltea Date: Wed, 03 Dec 2025 20:27:52 +0200 Subject: [PATCH 1/4] drm/bridge: Add ->detect_ctx hook and drm_bridge_detect_ctx() 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: quoted-printable Message-Id: <20251203-dw-hdmi-qp-scramb-v1-1-836fe7401a69@collabora.com> References: <20251203-dw-hdmi-qp-scramb-v1-0-836fe7401a69@collabora.com> In-Reply-To: <20251203-dw-hdmi-qp-scramb-v1-0-836fe7401a69@collabora.com> To: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Sandy Huang , =?utf-8?q?Heiko_St=C3=BCbner?= , Andy Yan Cc: kernel@collabora.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org X-Mailer: b4 0.14.3 Add an atomic variant of the ->detect callback and a new helper to call the hook while passing an optional drm_modeset_acquire_ctx reference. When both ->detect_ctx and ->detect are defined, the latter is ignored. If acquire_ctx is unset, the function takes care of the locking, while also handling EDEADLK. Signed-off-by: Cristian Ciocaltea --- drivers/gpu/drm/drm_bridge.c | 58 ++++++++++++++++++++++++++++++++++++++++= ++++ include/drm/drm_bridge.h | 30 +++++++++++++++++++++++ 2 files changed, 88 insertions(+) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 8f355df883d8..1fe03bcf2fc1 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -1280,6 +1280,64 @@ drm_bridge_detect(struct drm_bridge *bridge, struct = drm_connector *connector) } EXPORT_SYMBOL_GPL(drm_bridge_detect); =20 +/** + * drm_bridge_detect_ctx - check if anything is attached to the bridge out= put + * @bridge: bridge control structure + * @connector: attached connector + * @ctx: acquire_ctx, or NULL to let this function handle locking + * + * If the bridge supports output detection, as reported by the + * DRM_BRIDGE_OP_DETECT bridge ops flag, call &drm_bridge_funcs.detect_ctx + * or &drm_bridge_funcs.detect for the bridge and return the connection st= atus. + * Otherwise return connector_status_unknown. + * + * When both @ctx and &drm_bridge_funcs.detect_ctx are not set, this helper + * function is equivalent to drm_bridge_detect() above. + * + * RETURNS: + * The detection status on success, or connector_status_unknown if the bri= dge + * doesn't support output detection. + * If @ctx is set, it might also return -EDEADLK. + */ +int drm_bridge_detect_ctx(struct drm_bridge *bridge, + struct drm_connector *connector, + struct drm_modeset_acquire_ctx *ctx) +{ + if (!(bridge->ops & DRM_BRIDGE_OP_DETECT)) + return connector_status_unknown; + + if (bridge->funcs->detect_ctx) { + struct drm_modeset_acquire_ctx br_ctx; + int ret; + + if (ctx) + return bridge->funcs->detect_ctx(bridge, connector, ctx); + + drm_modeset_acquire_init(&br_ctx, 0); +retry: + ret =3D drm_modeset_lock(&connector->dev->mode_config.connection_mutex, + &br_ctx); + if (!ret) + ret =3D bridge->funcs->detect_ctx(bridge, connector, &br_ctx); + + if (ret =3D=3D -EDEADLK) { + drm_modeset_backoff(&br_ctx); + goto retry; + } + + if (ret < 0) + ret =3D connector_status_unknown; + + drm_modeset_drop_locks(&br_ctx); + drm_modeset_acquire_fini(&br_ctx); + + return ret; + } + + return bridge->funcs->detect(bridge, connector); +} +EXPORT_SYMBOL_GPL(drm_bridge_detect_ctx); + /** * drm_bridge_get_modes - fill all modes currently valid for the sink into= the * @connector diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index 0ff7ab4aa868..e11a1b39ef33 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -664,6 +664,33 @@ struct drm_bridge_funcs { enum drm_connector_status (*detect)(struct drm_bridge *bridge, struct drm_connector *connector); =20 + /** + * @detect_ctx: + * + * Check if anything is attached to the bridge output. + * + * This callback is optional, if not implemented the bridge will be + * considered as always having a component attached to its output. + * Bridges that implement this callback shall set the + * DRM_BRIDGE_OP_DETECT flag in their &drm_bridge->ops. + * + * This is the atomic version of &drm_bridge_funcs.detect. + * + * To avoid races against concurrent connector state updates, the + * helper libraries always call this with ctx set to a valid context, + * and &drm_mode_config.connection_mutex will always be locked with + * the ctx parameter set to this ctx. This allows taking additional + * locks as required. + * + * RETURNS: + * + * &drm_connector_status indicating the bridge output status, + * or the error code returned by drm_modeset_lock(), -EDEADLK. + */ + int (*detect_ctx)(struct drm_bridge *bridge, + struct drm_connector *connector, + struct drm_modeset_acquire_ctx *ctx); + /** * @get_modes: * @@ -1527,6 +1554,9 @@ drm_atomic_helper_bridge_propagate_bus_fmt(struct drm= _bridge *bridge, =20 enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge, struct drm_connector *connect= or); +int drm_bridge_detect_ctx(struct drm_bridge *bridge, + struct drm_connector *connector, + struct drm_modeset_acquire_ctx *ctx); int drm_bridge_get_modes(struct drm_bridge *bridge, struct drm_connector *connector); const struct drm_edid *drm_bridge_edid_read(struct drm_bridge *bridge, --=20 2.51.2