Re: [PATCH 5/6] drm/panel: simple: Innolux TV123WAM is actually P120ZDG-BF1

[Abhinav Kumar]

On 2018-10-25 11:45, Doug Anderson wrote:
> Hi,
>
> On Thu, Oct 25, 2018 at 11:13 AM Sean Paul <sean@xxxxxxxxxx> wrote:
> > On Mon, Oct 22, 2018 at 01:46:38PM -0700, Douglas Anderson wrote:
> > > As far as I can tell the panel that was added in commit da50bd4258db
> > > ("drm/panel: simple: Add Innolux TV123WAM panel driver support")
> > > wasn't actually an Innolux TV123WAM but was actually an Innolux
> > > P120ZDG-BF1.
> > >
> > > As far as I can tell the Innolux TV123WAM isn't a real panel and but
> > > it's a mosh between the TI TV123WAM and the Innolux P120ZDG-BF1.
> > > Let's unmosh.
> > >
> > > Here's my evidence:
> > >
> > > * Searching for TV123WAM on the Internet turns up a TI panel.  While
> > >   it's possible that an Innolux panel has the same model number as the
> > >   TI Panel, it seems a little doubtful.  Looking up the datasheet from
> > >   the TI Panel shows that it's 1920 x 1280 and 259.2 mm x 172.8 mm.
> > >
> > > * As far as I know, the patch adding the Innolux Panel was supposed to
> > >   be for the board that's sitting in front of me as I type this
> > >   (support for that board is not yet upstream).  On the back of that
> > >   panel I see Innolux P120ZDZ-EZ1 rev B1.
> > >
> > > * Someone pointed me at a datasheet that's supposed to be for the
> > >   panel in front of me (sorry, I can't share the datasheet).  That
> > >   datasheet has the string "p120zdg-bf1"
> > >
> > > * If I search for "P120ZDG-BF1" on the Internet I get hits for panels
> > >   that are 2160x1440.  They don't have datasheets, but the fact that
> > >   the resolution matches is a good sign.
> > >
> > > In any case, let's update the name and also the physical size to match
> > > the correct panel.
> > >
> > > Fixes: da50bd4258db ("drm/panel: simple: Add Innolux TV123WAM panel driver support")
> > > Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> > > Cc: Sandeep Panda <spanda@xxxxxxxxxxxxxx>
> > > ---
If Rob is onboard with this binding change, please feel free to add
Reviewed-by: Abhinav Kumar <abhinavk@xxxxxxxxxxxxxx>
> > >
> > >  drivers/gpu/drm/panel/panel-simple.c | 14 +++++++-------
> > >  1 file changed, 7 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> > > index 937e97490c30..7ee1abc5d81b 100644
> > > --- a/drivers/gpu/drm/panel/panel-simple.c
> > > +++ b/drivers/gpu/drm/panel/panel-simple.c
> > > @@ -1370,7 +1370,7 @@ static const struct panel_desc innolux_n156bge_l21 = {
> > >       },
> > >  };
> > >
> > > -static const struct drm_display_mode innolux_tv123wam_mode = {
> > > +static const struct drm_display_mode innolux_p120zdg_bf1_mode = {
> > >       .clock = 206016,
> > >       .hdisplay = 2160,
> > >       .hsync_start = 2160 + 48,
> > > @@ -1384,13 +1384,13 @@ static const struct drm_display_mode innolux_tv123wam_mode = {
> > >       .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
> > >  };
> > >
> > > -static const struct panel_desc innolux_tv123wam = {
> > > -     .modes = &innolux_tv123wam_mode,
> > > +static const struct panel_desc innolux_p120zdg_bf1 = {
> > > +     .modes = &innolux_p120zdg_bf1_mode,
> > >       .num_modes = 1,
> > >       .bpc = 8,
> > >       .size = {
> > > -             .width = 259,
> > > -             .height = 173,
> > > +             .width = 254,
> > > +             .height = 169,
> > >       },
> > >       .delay = {
> > >               .prepare = 200,
> > > @@ -2454,8 +2454,8 @@ static const struct of_device_id platform_of_match[] = {
> > >               .compatible = "innolux,n156bge-l21",
> > >               .data = &innolux_n156bge_l21,
> > >       }, {
> > > -             .compatible = "innolux,tv123wam",
> >
> > I think we should update the struct, but we might want to keep this 
> > around.
> > Given the tv123wam panel is TI, we're likely not going to have a 
> > collision on
> > innolux,...
> >
> > That said, I'll defer to robh on this one, I'm not sure if changing 
> > names is
> > cool once the bindings have hit mainline.
>
> Whoops, I missed Rob on this patch--just had him on the bindings one.
>
> ...generally I believe Rob seems to be OK with wiping out backward
> compatibility for things like this when the previous binding is super
> new and there's no evidence that anyone ever used it (like if it was
> added for a specific board and that board doesn't have a fully
> functional DT anyway).
>
> In this particular case I'm 99.9999% certain nobody is using the
> existing binding.  If someone crawls out of the woodwork and says this
> patch broke them, it would be trivially easy to add the backward
> compatible string later.
>
> Obviously Rob can feel free to correct me if I'm wrong.
>
> I purposely put this patch at the end of the series so we can land the
> earlier ones and we can sit on this one for a little while if desired.
>
> -Doug