linux-kernel - Re: [PATCH] drm/panel: kingdisplay-kd097d04: Disable EoTp

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

Message-ID: <aeee5f47ef2842fde66bc66fc598ee4f007fc1c2.camel@googlemail.com>
Date: Tue, 28 Oct 2025 23:31:11 +0100
From: Christoph Fritz <chf.fritz@...glemail.com>
To: Sebastian Fleer <dev@...rp.de>
Cc: Neil Armstrong <neil.armstrong@...aro.org>, Jessica Zhang
 <jesszhan0024@...il.com>, 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>, dri-devel@...ts.freedesktop.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH] drm/panel: kingdisplay-kd097d04: Disable EoTp

Hi Sebastian

On Tue, 2025-10-28 at 22:38 +0100, Sebastian Fleer wrote:
> Since commit d97e71e44937 ("drm/bridge: synopsys: dw-mipi-dsi: enable EoTp by
> default") panel output on an Acer Chromebook Tab 10 (google-dru) is corrupted.
> The tablet I use is equipped with a kingdisplay-kd097d04 panel, disabling EoTp
> restores the correct functionality.
> 
> Fixes: d97e71e44937 ("drm/bridge: synopsys: dw-mipi-dsi: enable EoTp by default")

Just to clarify: This is not a fix for that commit, it is a fix for the
panel driver itself.

EoTp is the default in Linux, a panel driver cannot enable it, only
disable it.

Commit d97e71e44937 ("drm/bridge: synopsys: dw-mipi-dsi: enable EoTp by
default") fixed a bug in the synopsys dw-mipi-dsi because EoTp was not
enabled there by default.

Enabling EoTp in dw-mipi-dsi revealed an underlying issue in panel-
kingdisplay-kd097d04.

That same issue appears if one would connect this panel to a different
mipi-dsi core (because there EoTp is also enabled by default).

> Signed-off-by: Sebastian Fleer <dev@...rp.de>
> ---
>  drivers/gpu/drm/panel/panel-kingdisplay-kd097d04.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-kingdisplay-kd097d04.c b/drivers/gpu/drm/panel/panel-kingdisplay-kd097d04.c
> index 2fc7b0779b37..893af9b16756 100644
> --- a/drivers/gpu/drm/panel/panel-kingdisplay-kd097d04.c
> +++ b/drivers/gpu/drm/panel/panel-kingdisplay-kd097d04.c
> @@ -359,7 +359,7 @@ static int kingdisplay_panel_probe(struct mipi_dsi_device *dsi)
>  	dsi->lanes = 4;
>  	dsi->format = MIPI_DSI_FMT_RGB888;
>  	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
> -			  MIPI_DSI_MODE_LPM;
> +			  MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_NO_EOT_PACKET;
>  
>  	kingdisplay = devm_drm_panel_alloc(&dsi->dev, __typeof(*kingdisplay), base,
>  					   &kingdisplay_panel_funcs,