linux-kernel - Re: [PATCH v2] drm/msm/dsi: skip the wait for video mode done if not applicable

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 for Android: free password hash cracker in your pocket

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

Message-ID: <CAA8EJpqfvmUiOvwE0PE_pWMt7MHTdNeSo1nCA5xG5ykp4Ln6NQ@mail.gmail.com>
Date:   Sat, 16 Sep 2023 03:30:57 +0300
From:   Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To:     Abhinav Kumar <quic_abhinavk@...cinc.com>
Cc:     freedreno@...ts.freedesktop.org, Rob Clark <robdclark@...il.com>,
        Sean Paul <sean@...rly.run>,
        Marijn Suijten <marijn.suijten@...ainline.org>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>, Hai Li <hali@...eaurora.org>,
        dri-devel@...ts.freedesktop.org, quic_jesszhan@...cinc.com,
        quic_parellan@...cinc.com, linux-arm-msm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] drm/msm/dsi: skip the wait for video mode done if not applicable

On Fri, 15 Sept 2023 at 23:45, Abhinav Kumar <quic_abhinavk@...cinc.com> wrote:
>
> dsi_wait4video_done() API waits for the DSI video mode engine to
> become idle so that we can transmit the DCS commands in the
> beginning of BLLP. However, with the current sequence, the MDP
> timing engine is turned on after the panel's pre_enable() callback
> which can send out the DCS commands needed to power up the panel.
>
> During those cases, this API will always timeout and print out the
> error spam leading to long bootup times and log flooding.
>
> Fix this by checking if the DSI video engine was actually busy before
> waiting for it to become idle otherwise this is a redundant wait.
>
> changes in v2:
>         - move the reg read below the video mode check
>         - minor fixes in commit text
>
> Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/34
> Fixes: a689554ba6ed ("drm/msm: Initial add DSI connector support")
> Signed-off-by: Abhinav Kumar <quic_abhinavk@...cinc.com>

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>

> ---
>  drivers/gpu/drm/msm/dsi/dsi_host.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>


-- 
With best wishes
Dmitry