linux-kernel - Re: [PATCH v7 00/10] drm: add DRM HDMI Codec framework

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20241218-wild-red-manatee-bb2a34@houat>
Date: Wed, 18 Dec 2024 08:59:43 +0100
From: Maxime Ripard <mripard@...nel.org>
To: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>, 
	Dave Stevenson <dave.stevenson@...pberrypi.com>, Maíra Canal <mcanal@...lia.com>, 
	Raspberry Pi Kernel Maintenance <kernel-list@...pberrypi.com>
Cc: Andrzej Hajda <andrzej.hajda@...el.com>, 
	Neil Armstrong <neil.armstrong@...aro.org>, Robert Foss <rfoss@...nel.org>, 
	Laurent Pinchart <Laurent.pinchart@...asonboard.com>, Jonas Karlman <jonas@...boo.se>, 
	Jernej Skrabec <jernej.skrabec@...il.com>, Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
	Thomas Zimmermann <tzimmermann@...e.de>, David Airlie <airlied@...il.com>, 
	Simona Vetter <simona@...ll.ch>, Jaroslav Kysela <perex@...ex.cz>, Takashi Iwai <tiwai@...e.com>, 
	Liam Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>, Phong LE <ple@...libre.com>, 
	Inki Dae <inki.dae@...sung.com>, Seung-Woo Kim <sw0312.kim@...sung.com>, 
	Kyungmin Park <kyungmin.park@...sung.com>, Krzysztof Kozlowski <krzk@...nel.org>, 
	Alim Akhtar <alim.akhtar@...sung.com>, Russell King <linux@...linux.org.uk>, 
	Chun-Kuang Hu <chunkuang.hu@...nel.org>, Philipp Zabel <p.zabel@...gutronix.de>, 
	Matthias Brugger <matthias.bgg@...il.com>, 
	AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>, Sandy Huang <hjc@...k-chips.com>, 
	Heiko Stübner <heiko@...ech.de>, Andy Yan <andy.yan@...k-chips.com>, 
	Alain Volmat <alain.volmat@...s.st.com>, Raphael Gallais-Pou <rgallaispou@...il.com>, 
	Jani Nikula <jani.nikula@...ux.intel.com>, dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org, 
	linux-sound@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, 
	linux-samsung-soc@...r.kernel.org, linux-mediatek@...ts.infradead.org, 
	linux-rockchip@...ts.infradead.org
Subject: Re: [PATCH v7 00/10] drm: add DRM HDMI Codec framework

On Wed, Dec 18, 2024 at 07:24:23AM +0200, Dmitry Baryshkov wrote:
> On Tue, 17 Dec 2024 at 19:21, Maxime Ripard <mripard@...nel.org> wrote:
> > On Tue, Dec 17, 2024 at 02:40:22AM +0200, Dmitry Baryshkov wrote:
> > > While porting lt9611 DSI-to-HDMI bridge driver to use HDMI Connector
> > > framework, I stumbled upon an issue while handling the Audio InfoFrames.
> > > The HDMI codec callbacks weren't receiving the drm_atomic_state, so
> > > there was no simple way to get the drm_connector that stayed at the end
> > > of the bridge chain. At the same point the drm_hdmi_connector functions
> > > expected to get drm_connector instance.
> > >
> > > While looking for a way to solve the issue, I stumbled upon several
> > > deficiencies in existing hdmi_codec_ops implementations. Only few of the
> > > implementations were able to handle codec's 'plugged' callback. One
> > > third of the drivers didn't implement the get_eld() callback.
> > >
> > > Most of the issues can be solved if drm_connector handles
> > > hdmi-audio-codec on its own, delegating functionality to the actual
> > > implementation, be it a driver that implements drm_connector or
> > > drm_bridge.
> > >
> > > Implement such high-level framework, adding proper support for Audio
> > > InfoFrame generation to the LT9611 driver.
> > >
> > > Several design decisions to be kept in mind:
> > >
> > > - drm_connector_hdmi_codec is kept as simple as possible. It implements
> > >   generic functionality (ELD, hotplug, registration).
> > >
> > > - drm_hdmi_connector sets up HDMI codec device if the connector
> > >   is setup correspondingly (either I2S or S/PDIF is marked as
> > >   supported).
> > >
> > > - drm_bridge_connector provides a way to link HDMI audio codec
> > >   funcionality in the drm_bridge with the drm_connector_hdmi_codec
> > >   framework.
> > >
> > > - It might be worth reverting the no_i2s_capture / no_spdif_capture
> > >   bits. Only TDA889x driver sets them, while it's safe to assume that
> > >   most of HDMI / DP devices do not support ARC / capture. I think the
> > >   drivers should opt-in capture support rather than having to opt-out of
> > >   it.
> >
> > Sorry if this isn't clear to me and I'm quite late to the party, but did
> > you test this on vc4 with both a pi3 and pi4, or was it just compile
> > tested?
> 
> LT9611 is actually tested, VC4 is only compile-tested. Should I put an RFT tag?

Yeah, we definitely need to test it on the pi3 (polling-based) and the
pi4 (irq-based) at least.

Dave, Maira, could you give it a try?

Maxime

Download attachment "signature.asc" of type "application/pgp-signature" (274 bytes)