From nobody Tue Feb 10 12:57:28 2026 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (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 93B8E329C77 for ; Sat, 7 Feb 2026 09:56:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.187 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770458182; cv=none; b=UhbdljBn1onfG9QXl5KyND/ejTbiYDUnBsbqg2D0db1c0lqFycEEBOfn+0CWS+dKr+JUOKj0Ehsp/MuE7zFnJlAFvikjjph7YgdFYWIXAKvlAK4IxkUUcUVMLmVWmwblXA4cRRDGUslqhclpdmyaJIuKphXlVEP5e1dvrd7ft5M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770458182; c=relaxed/simple; bh=puH0smDyxA9T2sNx3elyUD4mPKH/DFiEz5s7g59PTpI=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=djuq1heGwZlL//MobTRxQqssWC9PUbmEpnGHl53yojYct3K8V4TtonAG8dvrwCCUIGksdN7AZZ7/1mZubfj5GYlBYDNT6F1WKL9FStmDDX3X39G8k9LZH6Pf2S5Twj5eIHtWUoWWos14dRGzbpBWUU/pYCahH3JH2vHn0L2fZ10= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=uvbNAkjC; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=uvbNAkjC; arc=none smtp.client-ip=45.249.212.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="uvbNAkjC"; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="uvbNAkjC" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=w5YjtmU3XIdKBFCtWP/MVXkS+YCxvpDP54PIIdNpk5A=; b=uvbNAkjC4gSV8j6ELUnvYmYwr6i1a77KL6HyCAIpyJcAvx+x73melXbqWsA1TiG/AgcokawbA Tqatu1M6b48ScCOBhQpq6s1/dkr/45473n3y+7GZ1pNWnJUn8eG/I7G1DYMQaYaD0QRh/vghOEZ JZO2kED9E9hjaZduqN+ZdZg= Received: from canpmsgout07.his.huawei.com (unknown [172.19.92.160]) by szxga01-in.huawei.com (SkyGuard) with ESMTPS id 4f7RCc10wMz1BFsB for ; Sat, 7 Feb 2026 17:55:24 +0800 (CST) dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=w5YjtmU3XIdKBFCtWP/MVXkS+YCxvpDP54PIIdNpk5A=; b=uvbNAkjC4gSV8j6ELUnvYmYwr6i1a77KL6HyCAIpyJcAvx+x73melXbqWsA1TiG/AgcokawbA Tqatu1M6b48ScCOBhQpq6s1/dkr/45473n3y+7GZ1pNWnJUn8eG/I7G1DYMQaYaD0QRh/vghOEZ JZO2kED9E9hjaZduqN+ZdZg= Received: from mail.maildlp.com (unknown [172.19.163.127]) by canpmsgout07.his.huawei.com (SkyGuard) with ESMTPS id 4f7R7C0WvrzLlSZ; Sat, 7 Feb 2026 17:51:35 +0800 (CST) Received: from dggemv712-chm.china.huawei.com (unknown [10.1.198.32]) by mail.maildlp.com (Postfix) with ESMTPS id DA6F240363; Sat, 7 Feb 2026 17:56:10 +0800 (CST) Received: from kwepemq100007.china.huawei.com (7.202.195.175) by dggemv712-chm.china.huawei.com (10.1.198.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Sat, 7 Feb 2026 17:56:10 +0800 Received: from localhost.huawei.com (10.169.71.169) by kwepemq100007.china.huawei.com (7.202.195.175) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Sat, 7 Feb 2026 17:56:10 +0800 From: Yongbang Shi To: , , , , , , , , CC: , , , , , , , , Subject: [PATCH drm-dp 2/4] drm/hisilicon/hibmc: fix no showing when no connectors connected Date: Sat, 7 Feb 2026 17:48:35 +0800 Message-ID: <20260207094837.1468985-3-shiyongbang@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20260207094837.1468985-1-shiyongbang@huawei.com> References: <20260207094837.1468985-1-shiyongbang@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To kwepemq100007.china.huawei.com (7.202.195.175) Content-Type: text/plain; charset="utf-8" From: Lin He Our chip support KVM over IP feature, so hibmc driver need to support displaying without any connectors plugged in. If no connectors are connected, the vdac connector status should be set to 'connected' to ensure proper KVM display functionality. Additionally, for previous-generation products that may lack hardware link support and thus cannot detect the monitor, the same approach should be applied to ensure VGA display functionality. Add phys_state in the struct of dp and vdac to check all physical outputs. For get_modes: using BMC modes for connector if no display is attached to phys VGA cable, otherwise use EDID modes by drm_connector_helper_get_modes, because KVM doesn't provide EDID reads. Fixes: 4c962bc929f1 ("drm/hisilicon/hibmc: Add vga connector detect functio= ns") Reported-by: Thomas Zimmermann Closes: https://lore.kernel.org/all/0eb5c509-2724-4c57-87ad-74e4270d5a5a@su= se.de/ Signed-off-by: Lin He Signed-off-by: Yongbang Shi --- drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h | 1 + .../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c | 33 ++++++++---- .../gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h | 1 + .../gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c | 52 ++++++++++++------- 4 files changed, 59 insertions(+), 28 deletions(-) diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h b/drivers/gpu/drm/h= isilicon/hibmc/dp/dp_hw.h index 31316fe1ea8d..dfaeabd05d46 100644 --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h @@ -55,6 +55,7 @@ struct hibmc_dp { struct drm_dp_aux aux; struct hibmc_dp_cbar_cfg cfg; u32 irq_status; + int phys_state; }; =20 int hibmc_dp_hw_init(struct hibmc_dp *dp); diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c b/drivers/gpu/d= rm/hisilicon/hibmc/hibmc_drm_dp.c index 35dff7bfbf76..8fe2eb51a0b3 100644 --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c @@ -61,27 +61,38 @@ static int hibmc_dp_detect(struct drm_connector *connec= tor, { struct hibmc_dp *dp =3D to_hibmc_dp(connector); struct hibmc_dp_dev *dp_dev =3D dp->dp_dev; - int ret; + int ret =3D connector_status_disconnected; =20 if (dp->irq_status) { - if (dp_dev->hpd_status !=3D HIBMC_HPD_IN) - return connector_status_disconnected; + if (dp_dev->hpd_status !=3D HIBMC_HPD_IN) { + ret =3D connector_status_disconnected; + goto exit; + } } =20 - if (!hibmc_dp_get_dpcd(dp_dev)) - return connector_status_disconnected; + if (!hibmc_dp_get_dpcd(dp_dev)) { + ret =3D connector_status_disconnected; + goto exit; + } =20 - if (!dp_dev->is_branch) - return connector_status_connected; + if (!dp_dev->is_branch) { + ret =3D connector_status_connected; + goto exit; + } =20 if (drm_dp_read_sink_count_cap(connector, dp_dev->dpcd, &dp_dev->desc) && dp_dev->downstream_ports[0] & DP_DS_PORT_HPD) { ret =3D drm_dp_read_sink_count(dp_dev->aux); - if (ret > 0) - return connector_status_connected; + if (ret > 0) { + ret =3D connector_status_connected; + goto exit; + } } =20 - return connector_status_disconnected; +exit: + dp->phys_state =3D ret; + + return ret; } =20 static int hibmc_dp_mode_valid(struct drm_connector *connector, @@ -243,5 +254,7 @@ int hibmc_dp_init(struct hibmc_drm_private *priv) =20 connector->polled =3D DRM_CONNECTOR_POLL_HPD; =20 + dp->phys_state =3D connector_status_disconnected; + return 0; } diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h b/drivers/gpu/= drm/hisilicon/hibmc/hibmc_drm_drv.h index ca8502e2760c..6abb49b5107b 100644 --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h @@ -31,6 +31,7 @@ struct hibmc_vdac { struct drm_connector connector; struct i2c_adapter adapter; struct i2c_algo_bit_data bit_data; + int phys_state; }; =20 struct hibmc_drm_private { diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c b/drivers/gpu= /drm/hisilicon/hibmc/hibmc_drm_vdac.c index 841e81f47b68..502494cba541 100644 --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c @@ -25,27 +25,19 @@ static int hibmc_connector_get_modes(struct drm_connector *connector) { struct hibmc_vdac *vdac =3D to_hibmc_vdac(connector); - const struct drm_edid *drm_edid; - int count; + int count =3D 0; =20 - drm_edid =3D drm_edid_read_ddc(connector, &vdac->adapter); + if (vdac->phys_state =3D=3D connector_status_connected) + count =3D drm_connector_helper_get_modes(connector); =20 - drm_edid_connector_update(connector, drm_edid); - - if (drm_edid) { - count =3D drm_edid_connector_add_modes(connector); - if (count) - goto out; + if (count <=3D 0) { + drm_edid_connector_update(connector, NULL); + count =3D drm_add_modes_noedid(connector, + connector->dev->mode_config.max_width, + connector->dev->mode_config.max_height); + drm_set_preferred_mode(connector, 1024, 768); } =20 - count =3D drm_add_modes_noedid(connector, - connector->dev->mode_config.max_width, - connector->dev->mode_config.max_height); - drm_set_preferred_mode(connector, 1024, 768); - -out: - drm_edid_free(drm_edid); - return count; } =20 @@ -57,10 +49,32 @@ static void hibmc_connector_destroy(struct drm_connecto= r *connector) drm_connector_cleanup(connector); } =20 +static int hibmc_vdac_detect(struct drm_connector *connector, + struct drm_modeset_acquire_ctx *ctx, + bool force) +{ + struct hibmc_drm_private *priv =3D to_hibmc_drm_private(connector->dev); + struct hibmc_vdac *vdac =3D to_hibmc_vdac(connector); + + vdac->phys_state =3D drm_connector_helper_detect_from_ddc(connector, + ctx, force); + + /* If the DP connectors are disconnected, the hibmc_vdac_detect function + * must return a connected state to ensure KVM display functionality. + * Additionally, for previous-generation products that may lack hardware + * link support and thus cannot detect the monitor, hibmc_vdac_detect + * should also return a connected state. + */ + if (priv->dp.phys_state !=3D connector_status_connected) + return connector_status_connected; + + return vdac->phys_state; +} + static const struct drm_connector_helper_funcs hibmc_connector_helper_funcs =3D { .get_modes =3D hibmc_connector_get_modes, - .detect_ctx =3D drm_connector_helper_detect_from_ddc, + .detect_ctx =3D hibmc_vdac_detect, }; =20 static const struct drm_connector_funcs hibmc_connector_funcs =3D { @@ -130,6 +144,8 @@ int hibmc_vdac_init(struct hibmc_drm_private *priv) =20 connector->polled =3D DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DIS= CONNECT; =20 + vdac->phys_state =3D connector_status_connected; + return 0; =20 err: --=20 2.33.0