Re: [PATCH] drm/panel: sitronix-st7789v: fix sync flags for t28cp45tn89

[Marek Vasut]

On 9/24/25 11:46 PM, Sebastian Reichel wrote:
> From: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
>
> I planned to set the polarity of horizontal and vertical sync, but
> accidentally described vertical sync twice with different polarity
> instead.
>
> Note, that there is no functional change, because the driver only
> makes use of DRM_MODE_FLAG_P[HV]SYNC to divert from the default
> active-low polarity.
>
> Reported-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> Closes: https://lore.kernel.org/all/20250923132616.GH20765@xxxxxxxxxxxxxxxxxxxxxxxxxx/
> Fixes: a411558cc143 ("drm/panel: sitronix-st7789v: add Inanbo T28CP45TN89 support")
> Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
> ---
>   drivers/gpu/drm/panel/panel-sitronix-st7789v.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> index 04d91929eedda092b966b8cffdef5b267748f190..dedf0a390a88dd45a8179e2d22e872128c87cfda 100644
> --- a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> +++ b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> @@ -261,7 +261,7 @@ static const struct drm_display_mode t28cp45tn89_mode = {
>   	.vtotal = 320 + 8 + 4 + 4,
>   	.width_mm = 43,
>   	.height_mm = 57,
> -	.flags = DRM_MODE_FLAG_PVSYNC | DRM_MODE_FLAG_NVSYNC,
> +	.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_PVSYNC,
Is this panel somehow special with its NHSYNC / PVSYNC , compared to the 
other supported panels, which all use PHSYNC / PVSYNC ? I would expect 
all of these DSI TCON to use the same polarity, how come this one needs 
NHSYNC ?