Hi Christoph,
On 10/28/25 23:31, Christoph Fritz wrote:
> 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).
>
thanks for your clarification. You're right, this change is merely a
workaround for the kingdisplay panel.
However, I'm in favor of keeping the "Fixes:" line since using bisect,
commit d97e71e44937 ("drm/bridge: synopsys: dw-mipi-dsi: enable EoTp by
default") is found as the first commit that shows distorted output for
that panel.
But I can make the nature of the change more clear in the commit
message. Would that be OK for you?
Best regards,
Sebastian
>> Signed-off-by: Sebastian Fleer <[email protected]>
>> ---
>> 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,
