Re: [PATCH v7 3/5] drm/bridge: analogix_dp: Restore mandatory samsung DP DT properties

From: Damon Ding <damon.ding@rock-chips.com>
To: Luca Ceresoli <luca.ceresoli@bootlin.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>,
	Neil Armstrong <neil.armstrong@linaro.org>,
	Robert Foss <rfoss@kernel.org>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	David Airlie <airlied@gmail.com>, Simona Vetter <simona@ffwll.ch>,
	Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Sandy Huang <hjc@rock-chips.com>,
	Heiko Stuebner <heiko@sntech.de>,
	Andy Yan <andy.yan@rock-chips.com>,
	Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
	Jonas Karlman <jonas@kwiboo.se>,
	Jernej Skrabec <jernej.skrabec@gmail.com>,
	Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Sebastian Reichel <sebastian.reichel@collabora.com>,
	dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v7 3/5] drm/bridge: analogix_dp: Restore mandatory samsung DP DT properties
Date: Fri, 21 Aug 2026 15:37:19 +0800	[thread overview]
Message-ID: <7087887e-95e9-4253-a86e-c074eef950fd@rock-chips.com> (raw)
In-Reply-To: <178714408666.358642.12912882529209046607.b4-review@b4>

Hi Luca,

On 8/19/2026 8:54 PM, Luca Ceresoli wrote:
>> Revert the change that made samsung,link-rate and samsung,lane-count
>> optional for Exynos DP. Add error checking to fail probe early if the
>> required DT properties are missing.
>>
>> If these properties are zero, &link_train.link_rate and
>> &link_train.lane_count used in the subsequent link training flow will
>> also be zero, resulting in link training failure. Although all existing
>> Exynos DP DT nodes already contain these two properties, this potential
>> logic issue still needs to be fixed.
>>
>> Fixes: 0d0abd894ead ("drm: bridge: analogix/dp: add max link rate and lane count limit for RK3288")
> 
> If it's a fix, please add 'Cc: stable' too.
> 
> Also please add to the commit message the detailed analysis you wrote in
> the v6 discussion, so that it will easy to find in the git history, in case
> it's needed in the future.
> 
> With that added you can add: Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
> 
> 

Yes, will do in v8.

Best regards,
Damon