linux-kernel - Re: [PATCH 3/4] drm/vc4: use new helper to get ACR values

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <esgb42dyhpjixm62tfk2nfzdiygnfn4bcwq4zn7rhydmt4np2q@7v77p7kveb4e>
Date: Mon, 10 Mar 2025 22:18:04 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Maxime Ripard <mripard@...nel.org>
Cc: Dmitry Baryshkov <lumag@...nel.org>, 
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, Thomas Zimmermann <tzimmermann@...e.de>, 
	David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, Rob Clark <robdclark@...il.com>, 
	Abhinav Kumar <quic_abhinavk@...cinc.com>, Sean Paul <sean@...rly.run>, 
	Marijn Suijten <marijn.suijten@...ainline.org>, Dave Stevenson <dave.stevenson@...pberrypi.com>, 
	Maíra Canal <mcanal@...lia.com>, Raspberry Pi Kernel Maintenance <kernel-list@...pberrypi.com>, 
	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>, 
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org, 
	freedreno@...ts.freedesktop.org
Subject: Re: [PATCH 3/4] drm/vc4: use new helper to get ACR values

On Mon, Mar 10, 2025 at 03:51:53PM +0100, Maxime Ripard wrote:
> On Sun, Mar 09, 2025 at 10:13:58AM +0200, Dmitry Baryshkov wrote:
> > From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
> > 
> > Use drm_hdmi_acr_get_n_cts() helper instead of calculating N and CTS
> > values in the VC4 driver.
> > 
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
> > ---
> >  drivers/gpu/drm/vc4/vc4_hdmi.c | 10 +++-------
> >  drivers/gpu/drm/vc4/vc4_hdmi.h |  7 +++++++
> >  2 files changed, 10 insertions(+), 7 deletions(-)
> > 

> > diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h
> > index e3d989ca302b72533c374dfa3fd0d5bd7fe64a82..0a775dbfe99d45521f3d0a2016555aefa81d7934 100644
> > --- a/drivers/gpu/drm/vc4/vc4_hdmi.h
> > +++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
> > @@ -211,6 +211,13 @@ struct vc4_hdmi {
> >  	 * KMS hooks. Protected by @mutex.
> >  	 */
> >  	enum hdmi_colorspace output_format;
> > +
> > +	/**
> > +	 * @tmds_char_rate: Copy of
> > +	 * @drm_connector_state.hdmi.tmds_char_rate for use outside of
> > +	 * KMS hooks. Protected by @mutex.
> > +	 */
> > +	unsigned long long tmds_char_rate;
> >  };
> 
> This should be in drm_connector_hdmi if it's useful

That would mean bringing the state to a non-state structure on the
framework level. Is it fine from your POV? Is it also fine to use
drm_connector.mutex for protecting this? Or should we be using something
like drm_connector_hdmi.infoframes.mutex (maybe after moving it from
.infoframes to the top level)?

-- 
With best wishes
Dmitry