From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 9A48E31196B for ; Mon, 1 Sep 2025 10:05:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756721110; cv=none; b=M+eXdmLCQ9dLqpjbluI8X6I3JG5nOd4T4y1PHLJF1wjWqjsjZ1H0wFrRxZ+Z+YpMgLn6q0mfFv1b0hAe20ggvnlhHvUX5+vzQBZFklHlyzD2m3CnyKM1oquuAWa/c3M1IwOGApsKfkD20q6j67irzZt9mHlYvI82H+w2poa+jNQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756721110; c=relaxed/simple; bh=93jT9/ShH+uGR5IWGdBye1SHTwQemNaJlB1PuQcBg+g=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=oHO066baKvZPx4cqqEW65qxPn5SjDU2w50Idd3Uw18ikyh4RuIFJPRhR/mYN8KWXW+hf/3c2bpVRPyZnvPhb0D+zpp0EJHVY5aXgTVQUNJ4mBuSTINyIdJ1frKedo16zo3MJzSQcsE88fObu2u9qyVC/LyVFeLFWUtQu0/8sQC0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=X7To+hju; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="X7To+hju" Received: from [192.168.88.20] (91-158-153-178.elisa-laajakaista.fi [91.158.153.178]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 2CFAA3A2; Mon, 1 Sep 2025 12:03:58 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1756721039; bh=93jT9/ShH+uGR5IWGdBye1SHTwQemNaJlB1PuQcBg+g=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=X7To+hjucybukCA1gk60DljaFLBha4PVrKyKQjPRYvq2CkZhLj2qlsdMRSTMxAmsR BywC4A3vwzQyH0DPHaUbvP4FVa/aiFiGQWvnd8oQcGQoUlTJlSTPiB5EwzxKyOPjp/ PhrWbi89XGH02Cxal3m2Nr/zJl6YObs2cGzy19Cg= Message-ID: <6fa1a8d5-149e-437d-aef0-587c49957197@ideasonboard.com> Date: Mon, 1 Sep 2025 13:05:02 +0300 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 3/6] drm/bridge: cadence: cdns-mhdp8546-core: Set the mhdp connector earlier in atomic_enable() To: Harikrishna Shenoy Cc: jonas@kwiboo.se, jernej.skrabec@gmail.com, maarten.lankhorst@linux.intel.com, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch, lyude@redhat.com, luca.ceresoli@bootlin.com, viro@zeniv.linux.org.uk, andy.yan@rock-chips.com, linux@treblig.org, javierm@redhat.com, linux-kernel@vger.kernel.org, devarsht@ti.com, j-choudhary@ti.com, u-kumar1@ti.com, s-jain1@ti.com, andrzej.hajda@intel.com, neil.armstrong@linaro.org, rfoss@kernel.org, Laurent.pinchart@ideasonboard.com, mripard@kernel.org, lumag@kernel.org, dianders@chromium.org, dri-devel@lists.freedesktop.org References: <20250811075904.1613519-1-h-shenoy@ti.com> <20250811075904.1613519-4-h-shenoy@ti.com> Content-Language: en-US From: Tomi Valkeinen Autocrypt: addr=tomi.valkeinen@ideasonboard.com; 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charset=UTF-8 Content-Transfer-Encoding: 7bit Hi, On 11/08/2025 10:59, Harikrishna Shenoy wrote: > 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 set the mhdp->connector > in atomic_enable() earlier to avoid possible NULL pointer. > > Fixes: c932ced6b585 ("drm/tidss: Update encoder/bridge chain connect model") > Signed-off-by: Jayesh Choudhary > --- > .../drm/bridge/cadence/cdns-mhdp8546-core.c | 20 +++++++++---------- > 1 file changed, 10 insertions(+), 10 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c > index c2ce3d6e5a88..b2f5a48cac2d 100644 > --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c > +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c > @@ -1759,12 +1759,21 @@ static void cdns_mhdp_atomic_enable(struct drm_bridge *bridge, > struct drm_bridge_state *new_state; > const struct drm_display_mode *mode; > u32 resp; > - int ret; > + int ret = 0; > > dev_dbg(mhdp->dev, "bridge enable\n"); > > mutex_lock(&mhdp->link_mutex); > > + mhdp->connector = drm_atomic_get_new_connector_for_encoder(state, > + bridge->encoder); > + if (WARN_ON(!mhdp->connector)) > + goto out; > + > + conn_state = drm_atomic_get_new_connector_state(state, mhdp->connector); > + if (WARN_ON(!conn_state)) > + goto out; You are just moving code here, but... Shouldn't these be errors? If I read this right, ret is 0 here, and thus if we hit either of those issues above, we'll return 0. Tomi > + > if (mhdp->plugged && !mhdp->link_up) { > ret = cdns_mhdp_link_up(mhdp); > if (ret < 0) > @@ -1784,15 +1793,6 @@ static void cdns_mhdp_atomic_enable(struct drm_bridge *bridge, > cdns_mhdp_reg_write(mhdp, CDNS_DPTX_CAR, > resp | CDNS_VIF_CLK_EN | CDNS_VIF_CLK_RSTN); > > - mhdp->connector = drm_atomic_get_new_connector_for_encoder(state, > - bridge->encoder); > - if (WARN_ON(!mhdp->connector)) > - goto out; > - > - conn_state = drm_atomic_get_new_connector_state(state, mhdp->connector); > - if (WARN_ON(!conn_state)) > - goto out; > - > if (mhdp->hdcp_supported && > mhdp->hw_state == MHDP_HW_READY && > conn_state->content_protection ==