Hello Marek, On Thu, Sep 25, 2025 at 02:15:41AM +0200, Marek Vasut wrote: > On 9/24/25 11:46 PM, Sebastian Reichel wrote: > > From: Sebastian Reichel <sebastian.reic...@collabora.com> > > > > 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+rene...@ideasonboard.com> > > Closes: > > https://lore.kernel.org/all/20250923132616.gh20...@pendragon.ideasonboard.com/ > > Fixes: a411558cc143 ("drm/panel: sitronix-st7789v: add Inanbo T28CP45TN89 > > support") > > Signed-off-by: Sebastian Reichel <sebastian.reic...@collabora.com> > > --- > > 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 ?
I wrote this based on reverse engineering incl. quite a bit try-and-error and don't have very good data about the panel. Using DRM_MODE_FLAG_PHSYNC like all the other panels results in garbage data on the display. Greetings, -- Sebastian
signature.asc
Description: PGP signature
