From nobody Sun Feb 8 18:31:14 2026 Received: from fllvem-ot03.ext.ti.com (fllvem-ot03.ext.ti.com [198.47.19.245]) (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 C6D5B302CCA for ; Tue, 14 Oct 2025 09:46:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.19.245 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760435199; cv=none; b=FLVBpFS9YrUHEIB4UF9Eqes223tlqXoCcwrPHtrVt1UySPu9vZakBo/9W5IVIn4NbISaZfLjy8di+vgQF/TiRVOFrwOSaLyx8KwIDOvTrXENTPaNHZIUxRiOOpzgLN9RPW/kjeRfz0LGbgbL5rS+uuoUYKNezuie5JyC6jGk7kQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760435199; c=relaxed/simple; bh=oWDM8Y0QzM1M/9gOZ7msqyFqaNWOuZL64iKMoTU5ll8=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=IWyrNyFFP55bKuSu//nAGCPM8XmK1af8ErgqTGiDyWBcYd8jmAd7cNr6RYRsMIBd6OpLgFekdT+GdUBoUcT7//+213nxtp1Sg9y+zdf4icUBSBu8T6zf2T1E65R29tlfJzF+6kXDb2v+Rt5TKR9SqiT7wIeoRz/FW8hmahv1NYg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com; spf=pass smtp.mailfrom=ti.com; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b=l3RLF2i0; arc=none smtp.client-ip=198.47.19.245 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ti.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="l3RLF2i0" Received: from fllvem-sh04.itg.ti.com ([10.64.41.54]) by fllvem-ot03.ext.ti.com (8.15.2/8.15.2) with ESMTP id 59E9jhJd1039165; Tue, 14 Oct 2025 04:45:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1760435143; bh=T6S2MvM9uF1TV1afGaorNdjfES/u5wtrBI7oyO7jP4o=; h=From:To:Subject:Date:In-Reply-To:References; b=l3RLF2i0kWYJH1mOOboT+5MB4EWPjdg185kqalxxRSGB7P7PCWC5ltCvU1Mju+sW1 76SSQUDoFeQg3MaKcybqFvNcueo7JVCuaz8HyWMc2DYZtM3Jw6tNhnrhB54fxJie89 afFPiQN+6+pb90T9HEY0NhmpfA36bBxUB3y0M1mU= Received: from DLEE204.ent.ti.com (dlee204.ent.ti.com [157.170.170.84]) by fllvem-sh04.itg.ti.com (8.18.1/8.18.1) with ESMTPS id 59E9jgnC3713461 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 14 Oct 2025 04:45:42 -0500 Received: from DLEE203.ent.ti.com (157.170.170.78) by DLEE204.ent.ti.com (157.170.170.84) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.20; Tue, 14 Oct 2025 04:45:42 -0500 Received: from lelvem-mr06.itg.ti.com (10.180.75.8) by DLEE203.ent.ti.com (157.170.170.78) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.20 via Frontend Transport; Tue, 14 Oct 2025 04:45:42 -0500 Received: from hkshenoy.dhcp.ti.com (hkshenoy.dhcp.ti.com [172.24.235.208]) by lelvem-mr06.itg.ti.com (8.18.1/8.18.1) with ESMTP id 59E9jSjT3359281; Tue, 14 Oct 2025 04:45:35 -0500 From: Harikrishna Shenoy To: , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v8 1/6] drm/bridge: cadence: cdns-mhdp8546-core: Set the mhdp connector earlier in atomic_enable() Date: Tue, 14 Oct 2025 15:15:22 +0530 Message-ID: <20251014094527.3916421-2-h-shenoy@ti.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20251014094527.3916421-1-h-shenoy@ti.com> References: <20251014094527.3916421-1-h-shenoy@ti.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-C2ProcessedOrg: 333ef613-75bf-4e12-a4b1-8e3623f5dcea Content-Type: text/plain; charset="utf-8" From: Jayesh Choudhary In case if we get errors in cdns_mhdp_link_up() or cdns_mhdp_reg_read() in atomic_enable, we will go to cdns_mhdp_modeset_retry_fn() and will hit NULL pointer while trying to access the mutex. We need the connector to be set before that. Unlike in legacy !(DBANC) cases, we do not have connector initialised in bridge_attach(), so add the mhdp->connector_ptr in device structure to handle both DBANC and !DBANC case and set it in atomic_enable() earlier to avoid possible NULL pointer dereference in recovery paths like modeset_retry_fn() with the DBANC flag set. Fixes: c932ced6b585 ("drm/tidss: Update encoder/bridge chain connect model") Signed-off-by: Jayesh Choudhary Signed-off-by: Harikrishna Shenoy --- .../drm/bridge/cadence/cdns-mhdp8546-core.c | 29 ++++++++++--------- .../drm/bridge/cadence/cdns-mhdp8546-core.h | 1 + 2 files changed, 16 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/= gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index 38726ae1bf15..f3076e9cdabb 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -740,7 +740,7 @@ static void cdns_mhdp_fw_cb(const struct firmware *fw, = void *context) bridge_attached =3D mhdp->bridge_attached; spin_unlock(&mhdp->start_lock); if (bridge_attached) { - if (mhdp->connector.dev) + if (mhdp->connector_ptr && mhdp->connector_ptr->dev) drm_kms_helper_hotplug_event(mhdp->bridge.dev); else drm_bridge_hpd_notify(&mhdp->bridge, cdns_mhdp_detect(mhdp)); @@ -1636,6 +1636,7 @@ static int cdns_mhdp_connector_init(struct cdns_mhdp_= device *mhdp) return ret; } =20 + mhdp->connector_ptr =3D conn; drm_connector_helper_add(conn, &cdns_mhdp_conn_helper_funcs); =20 ret =3D drm_display_info_set_bus_formats(&conn->display_info, @@ -1915,17 +1916,25 @@ static void cdns_mhdp_atomic_enable(struct drm_brid= ge *bridge, struct cdns_mhdp_device *mhdp =3D bridge_to_mhdp(bridge); struct cdns_mhdp_bridge_state *mhdp_state; struct drm_crtc_state *crtc_state; - struct drm_connector *connector; struct drm_connector_state *conn_state; struct drm_bridge_state *new_state; const struct drm_display_mode *mode; u32 resp; - int ret; + int ret =3D 0; =20 dev_dbg(mhdp->dev, "bridge enable\n"); =20 mutex_lock(&mhdp->link_mutex); =20 + mhdp->connector_ptr =3D drm_atomic_get_new_connector_for_encoder(state, + bridge->encoder); + if (WARN_ON(!mhdp->connector_ptr)) + goto out; + + conn_state =3D drm_atomic_get_new_connector_state(state, mhdp->connector_= ptr); + if (WARN_ON(!conn_state)) + goto out; + if (mhdp->plugged && !mhdp->link_up) { ret =3D cdns_mhdp_link_up(mhdp); if (ret < 0) @@ -1945,15 +1954,6 @@ static void cdns_mhdp_atomic_enable(struct drm_bridg= e *bridge, cdns_mhdp_reg_write(mhdp, CDNS_DPTX_CAR, resp | CDNS_VIF_CLK_EN | CDNS_VIF_CLK_RSTN); =20 - connector =3D drm_atomic_get_new_connector_for_encoder(state, - bridge->encoder); - if (WARN_ON(!connector)) - goto out; - - conn_state =3D drm_atomic_get_new_connector_state(state, connector); - if (WARN_ON(!conn_state)) - goto out; - if (mhdp->hdcp_supported && mhdp->hw_state =3D=3D MHDP_HW_READY && conn_state->content_protection =3D=3D @@ -2030,6 +2030,7 @@ static void cdns_mhdp_atomic_disable(struct drm_bridg= e *bridge, if (mhdp->info && mhdp->info->ops && mhdp->info->ops->disable) mhdp->info->ops->disable(mhdp); =20 + mhdp->connector_ptr =3D NULL; mutex_unlock(&mhdp->link_mutex); } =20 @@ -2296,7 +2297,7 @@ static void cdns_mhdp_modeset_retry_fn(struct work_st= ruct *work) =20 mhdp =3D container_of(work, typeof(*mhdp), modeset_retry_work); =20 - conn =3D &mhdp->connector; + conn =3D mhdp->connector_ptr; =20 /* Grab the locks before changing connector property */ mutex_lock(&conn->dev->mode_config.mutex); @@ -2373,7 +2374,7 @@ static void cdns_mhdp_hpd_work(struct work_struct *wo= rk) int ret; =20 ret =3D cdns_mhdp_update_link_status(mhdp); - if (mhdp->connector.dev) { + if (mhdp->connector_ptr && mhdp->connector_ptr->dev) { if (ret < 0) schedule_work(&mhdp->modeset_retry_work); else diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h b/drivers/= gpu/drm/bridge/cadence/cdns-mhdp8546-core.h index bad2fc0c7306..a76775c76895 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h @@ -376,6 +376,7 @@ struct cdns_mhdp_device { struct mutex link_mutex; =20 struct drm_connector connector; + struct drm_connector *connector_ptr; struct drm_bridge bridge; =20 struct cdns_mhdp_link link; --=20 2.34.1