linux-kernel - Re: [PATCH v4 1/4] drm/dp: Add helper to set LTTPRs in transparent mode

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: <48c109bc-58c2-416a-ba6a-a15ca754f16d@quicinc.com>
Date: Wed, 8 Jan 2025 14:43:28 -0800
From: Abhinav Kumar <quic_abhinavk@...cinc.com>
To: Abel Vesa <abel.vesa@...aro.org>,
        Maarten Lankhorst
	<maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <mripard@...nel.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
        Karol Herbst <kherbst@...hat.com>, Lyude
 Paul <lyude@...hat.com>,
        Danilo Krummrich <dakr@...hat.com>,
        Jani Nikula
	<jani.nikula@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        Joonas
 Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Tvrtko Ursulin
	<tursulin@...ulin.net>,
        Rob Clark <robdclark@...il.com>,
        Dmitry Baryshkov
	<dmitry.baryshkov@...aro.org>,
        Sean Paul <sean@...rly.run>,
        Marijn Suijten
	<marijn.suijten@...ainline.org>
CC: Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio
	<konradybcio@...nel.org>,
        Johan Hovold <johan@...nel.org>, <dri-devel@...ts.freedesktop.org>,
        <linux-kernel@...r.kernel.org>, <nouveau@...ts.freedesktop.org>,
        <intel-gfx@...ts.freedesktop.org>, <intel-xe@...ts.freedesktop.org>,
        <linux-arm-msm@...r.kernel.org>, <freedreno@...ts.freedesktop.org>,
        Johan Hovold <johan+linaro@...nel.org>
Subject: Re: [PATCH v4 1/4] drm/dp: Add helper to set LTTPRs in transparent
 mode



On 1/8/2025 6:31 AM, Abel Vesa wrote:
> According to the DisplayPort standard, LTTPRs have two operating
> modes:
>   - non-transparent - it replies to DPCD LTTPR field specific AUX
>     requests, while passes through all other AUX requests
>   - transparent - it passes through all AUX requests.
> 
> Switching between this two modes is done by the DPTX by issuing
> an AUX write to the DPCD PHY_REPEATER_MODE register.
> 
> Add a generic helper that allows switching between these modes.
> 
> Also add a generic wrapper for the helper that handles the explicit
> disabling of non-transparent mode and its disable->enable sequence
> mentioned in the DP Standard v2.0 section 3.6.6.1. Do this in order
> to move this handling out of the vendor specific driver implementation
> into the generic framework.
> 
> Tested-by: Johan Hovold <johan+linaro@...nel.org>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
> Reviewed-by: Johan Hovold <johan+linaro@...nel.org>
> Signed-off-by: Abel Vesa <abel.vesa@...aro.org>
> ---
>   drivers/gpu/drm/display/drm_dp_helper.c | 62 +++++++++++++++++++++++++++++++++
>   include/drm/display/drm_dp_helper.h     |  2 ++
>   2 files changed, 64 insertions(+)
> 

Reviewed-by: Abhinav Kumar <quic_abhinavk@...cinc.com>