linux-kernel - Re: [PATCH v9 3/3] pmdomain: mediatek: Use OF-specific regulator API to get power domain supply

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] [day] [month] [year] [list]

Message-ID: <37648a24-03be-4acc-bfba-cf0ecb4b8f91@collabora.com>
Date: Wed, 9 Oct 2024 11:44:02 +0200
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>
To: Chen-Yu Tsai <wenst@...omium.org>, Ulf Hansson <ulf.hansson@...aro.org>,
 Matthias Brugger <matthias.bgg@...il.com>, Mark Brown <broonie@...nel.org>
Cc: devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
 linux-mediatek@...ts.infradead.org, linux-kernel@...r.kernel.org,
 linux-pm@...r.kernel.org, Douglas Anderson <dianders@...omium.org>,
 Johan Hovold <johan@...nel.org>,
 Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
 Pablo Sun <pablo.sun@...iatek.com>, Macpaul Lin <macpaul.lin@...iatek.com>,
 Sebastian Reichel <sebastian.reichel@...labora.com>
Subject: Re: [PATCH v9 3/3] pmdomain: mediatek: Use OF-specific regulator API
 to get power domain supply

Il 30/09/24 06:45, Chen-Yu Tsai ha scritto:
> The MediaTek power domain driver contains a hack that assigns the device
> node of the power domain to the struct device of the power domain
> controller in order to use the devres regulator API.
> 
> Now that there is a proper OF-specific regulator API, and even a devres
> version, replace the hack with proper code.
> 
> This change is incompatible with incomplete device trees. Instead of
> assigning the dummy regulator in cases where the power domain requires
> a supply but the device tree does not provide one, the driver will just
> error out. This will be seen on the MT8390 EVK, which is missing
> supplies for the IMG_VCORE and CAM_VCORE domains. And likely all the
> MediaTek EVBs, which have no power domain supplies specified. This is
> however the correct behavior. If the power domain's supply is missing,
> then it should not work. Relying on other parts of the system to keep
> the unattached regulator enabled is likely to break in ways less easier
> to understand.
> 
> Signed-off-by: Chen-Yu Tsai <wenst@...omium.org>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>