linux-kernel - Re: [PATCH v6 02/11] drm/mediatek: dp: Move AUX and panel poweron/off sequence to function

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: <ef08ffa7-436a-5da2-ff46-5697cab6d299@baylibre.com>
Date:   Thu, 20 Jul 2023 17:56:48 +0200
From:   Alexandre Mergnat <amergnat@...libre.com>
To:     AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>, chunkuang.hu@...nel.org
Cc:     p.zabel@...gutronix.de, airlied@...il.com, daniel@...ll.ch,
        matthias.bgg@...il.com, dri-devel@...ts.freedesktop.org,
        linux-mediatek@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, kernel@...labora.com,
        wenst@...omium.org, nfraprado@...labora.com
Subject: Re: [PATCH v6 02/11] drm/mediatek: dp: Move AUX and panel poweron/off
 sequence to function

Reviewed-by: Alexandre Mergnat <amergnat@...libre.com>

On 17/07/2023 16:14, AngeloGioacchino Del Regno wrote:
> Everytime we run bridge detection and/or EDID read we run a poweron
> and poweroff sequence for both the AUX and the panel; moreover, this
> is also done when enabling the bridge in the .atomic_enable() callback.
> 
> Move this power on/off sequence to a new mtk_dp_aux_panel_poweron()
> function as to commonize it.
> Note that, before this commit, in mtk_dp_bridge_atomic_enable() only
> the AUX was getting powered on but the panel was left powered off if
> the DP cable wasn't plugged in while now we unconditionally send a D0
> request and this is done for two reasons:
>   - First, whether this request fails or not, it takes the same time
>     and anyway the DP hardware won't produce any error (or, if it
>     does, it's ignorable because it won't block further commands)
>   - Second, training the link between a sleeping/standby/unpowered
>     display makes little sense.

-- 
Regards,
Alexandre