linux-kernel - [PATCH v3 0/2] "no-hpd" support in CDNS DP bridge driver

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Message-ID: <20250205115025.3133487-1-h-shenoy@ti.com>
Date: Wed, 5 Feb 2025 17:20:23 +0530
From: Harikrishna Shenoy <h-shenoy@...com>
To: <andrzej.hajda@...el.com>, <neil.armstrong@...aro.org>, <rfoss@...nel.org>,
        <Laurent.pinchart@...asonboard.com>, <jonas@...boo.se>,
        <jernej.skrabec@...il.com>, <simona@...ll.ch>,
        <maarten.lankhorst@...ux.intel.com>, <mripard@...nel.org>,
        <tzimmermann@...e.de>, <robh@...nel.org>, <krzk+dt@...nel.org>,
        <conor+dt@...nel.org>, <jani.nikula@...el.com>, <j-choudhary@...com>,
        <sui.jingfeng@...ux.dev>, <viro@...iv.linux.org.uk>,
        <r-ravikumar@...com>, <sjakhade@...ence.com>, <yamonkar@...ence.com>,
        <dri-devel@...ts.freedesktop.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: [PATCH v3 0/2] "no-hpd" support in CDNS DP bridge driver

In J721s2 EVM, DP0 HPD is not connected to correct HPD pin on SOC
which results in HPD detect as always connnected, so when display
is not connected driver continuously retries to read EDID and DPCD
registers.

To handle such cases add support for no hpd configuration in
cdns-mhdp driver.

Changelog v2->v3:
- update the mhdp->plugged status for no hpd configuration in
cdns_mhdp_bridge_detect()

Link to v2: 
<https://lore.kernel.org/all/20230406015207.GO9915@pendragon.ideasonboard.com/>

Rahul T R (2):
  dt-bindings: drm/bridge: Add no-hpd property
  drm: bridge: cdns-mhdp8546: Add support for no-hpd

 .../display/bridge/cdns,mhdp8546.yaml         |  6 +++
 .../drm/bridge/cadence/cdns-mhdp8546-core.c   | 54 ++++++++++++++++---
 .../drm/bridge/cadence/cdns-mhdp8546-core.h   |  1 +
 3 files changed, 55 insertions(+), 6 deletions(-)

-- 
2.34.1