linux-kernel - Re: [PATCH v9 2/9] platform/chrome: cros_ec

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: <CAGXv+5FVfSUo6aTfS6tGPZLT3gqBRj5i0h0gKk5EdifPj-4L8w@mail.gmail.com>
Date:   Mon, 9 Jan 2023 17:47:26 +0800
From:   Chen-Yu Tsai <wenst@...omium.org>
To:     Pin-yen Lin <treapking@...omium.org>
Cc:     Andrzej Hajda <andrzej.hajda@...el.com>,
        Neil Armstrong <neil.armstrong@...aro.org>,
        Robert Foss <robert.foss@...aro.org>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        Jonas Karlman <jonas@...boo.se>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Daniel Scally <djrscally@...il.com>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Sakari Ailus <sakari.ailus@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J . Wysocki" <rafael@...nel.org>,
        Prashant Malani <pmalani@...omium.org>,
        Benson Leung <bleung@...omium.org>,
        Guenter Roeck <groeck@...omium.org>,
        Marek Vasut <marex@...x.de>, devicetree@...r.kernel.org,
        Nícolas F . R . A . Prado 
        <nfraprado@...labora.com>, linux-acpi@...r.kernel.org,
        Allen Chen <allen.chen@....com.tw>,
        Javier Martinez Canillas <javierm@...hat.com>,
        dri-devel@...ts.freedesktop.org,
        Stephen Boyd <swboyd@...omium.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        Hsin-Yi Wang <hsinyi@...omium.org>,
        chrome-platform@...ts.linux.dev, Xin Ji <xji@...logixsemi.com>,
        linux-kernel@...r.kernel.org,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>
Subject: Re: [PATCH v9 2/9] platform/chrome: cros_ec_typec: Purge blocking
 switch devlinks

On Mon, Jan 9, 2023 at 4:41 PM Pin-yen Lin <treapking@...omium.org> wrote:
>
> From: Prashant Malani <pmalani@...omium.org>
>
> When using OF graph, the fw_devlink code will create links between the
> individual port driver (cros-ec-typec here) and the parent device for
> a Type-C switch (like mode-switch). Since the mode-switch will in turn
> have the usb-c-connector (i.e the child of the port driver) as a
> supplier, fw_devlink will not be able to resolve the cyclic dependency
> correctly.
>
> As a result, the mode-switch driver probe() never runs, so mode-switches
> are never registered. Because of that, the port driver probe constantly
> fails with -EPROBE_DEFER, because the Type-C connector class requires all
> switch devices to be registered prior to port registration.
>
> To break this deadlock and allow the mode-switch registration to occur,
> purge all the usb-c-connector nodes' absent suppliers. This eliminates
> the connector as a supplier for a switch and allows it to be probed.
>
> Signed-off-by: Prashant Malani <pmalani@...omium.org>
> Signed-off-by: Pin-yen Lin <treapking@...omium.org>


Reviewed-by: Chen-Yu Tsai <wenst@...omium.org>
Tested-by: Chen-Yu Tsai <wenst@...omium.org>

on MT8192 based Hayato (ASUS Chromebook Flip CM3200).