Re: [PATCH RFC 06/10] drm/panel/samsung-sofef01: Add panel driver for Sony Xperia 5 / 10 II

[Dmitry Baryshkov]

On 29/05/2023 23:58, Marijn Suijten wrote:
> On 2023-05-23 01:56:46, Dmitry Baryshkov wrote:
> > On Tue, 23 May 2023 at 01:32, Marijn Suijten
> > <marijn.suijten@xxxxxxxxxxxxxx> wrote:
> > > On 2023-05-22 04:19:45, Dmitry Baryshkov wrote:
> > > > On 22/05/2023 00:23, Marijn Suijten wrote:
> > > > > This SOFEF01-M Display-IC driver supports two modes with different
> > > > > compatibles to differentiate between slightly different physical sizes
> > > > > (panels) found on the Xperia 5 (6.1") and 10 II (6.0").
> > > > >
> > > > > It is currently also used to hardcode significantly higher fake porches
> > > > > for the Xperia 5, which are unused in transfers due to this being a
> > > > > command-mode panel but do have an effect on the clock rates set by
> > > > > dsi_host.c.  Without higher clock rates this panel fails to achieve
> > > > > 60fps and has significant tearing artifacts, while the same calculated
> > > > > clock rate works perfectly fine on the Xperia 10 II.
> > >
> > > <snip>
> > >
> > > > > +/* Sony Xperia 5 (kumano bahamut) */
> > > > > +static const struct drm_display_mode samsung_sofef01_m_bahamut_mode = {
> > > > > +   /*
> > > > > +    * WARNING: These massive porches are wrong/useless for CMDmode
> > > > > +    * (and not defined in downstream DTS) but necessary to bump dsi
> > > > > +    * clocks higher, so that we can achieve proper 60fps without tearing.
> > > > > +    */
> > > > > +   .clock = (1080 + 156 + 8 + 8) * (2520 + 2393 + 8 + 8) * 60 / 1000,
> > > > > +   .hdisplay = 1080,
> > > > > +   .hsync_start = 1080 + 156,
> > > > > +   .hsync_end = 1080 + 156 + 8,
> > > > > +   .htotal = 1080 + 156 + 8 + 8,
> > > > > +   .vdisplay = 2520,
> > > > > +   .vsync_start = 2520 + 2393,
> > > > > +   .vsync_end = 2520 + 2393 + 8,
> > > > > +   .vtotal = 2520 + 2393 + 8 + 8,
> > > > > +   .width_mm = 61,
> > > > > +   .height_mm = 142,
> > > > > +};
> > > > > +
> > > > > +/* Sony Xperia 10 II (seine pdx201) */
> > > > > +static const struct drm_display_mode samsung_sofef01_m_pdx201_mode = {
> > > > > +   .clock = (1080 + 8 + 8 + 8) * (2520 + 8 + 8 + 8) * 60 / 1000,
> > > > > +   .hdisplay = 1080,
> > > > > +   .hsync_start = 1080 + 8,
> > > > > +   .hsync_end = 1080 + 8 + 8,
> > > > > +   .htotal = 1080 + 8 + 8 + 8,
> > > > > +   .vdisplay = 2520,
> > > > > +   .vsync_start = 2520 + 8,
> > > > > +   .vsync_end = 2520 + 8 + 8,
> > > > > +   .vtotal = 2520 + 8 + 8 + 8,
> > > > > +   .width_mm = 60,
> > > > > +   .height_mm = 139,
> > > > > +};
> > > > > +
> > > > > +static const struct of_device_id samsung_sofef01_m_of_match[] = {
> > > > > +   { .compatible = "samsung,sofef01-m-bahamut", .data = &samsung_sofef01_m_bahamut_mode },
> > > > > +   { .compatible = "samsung,sofef01-m-pdx201", .data = &samsung_sofef01_m_pdx201_mode },
> > > >
> > > > Are there really two panels? Can we use one mode for both usecases?
> > >
> > > See the commit description where I explained exactly this: the panels
> > > have different dimensions (6.1" vs 6.0", hence different DPI) and I also
> > > abuse this to hack in higher clock rates via fake porches.
> > >
> > > I just ended up on a scary website that supposedly contains the panel
> > > names:
> > >
> > > - Xperia 5 (bahamut, 6.1"): AMB609TC01
> > > - Xperia 10 II (pdx201, 6.0"): AMS597UT01
> >
> > Great! From the patch description it was not obvious if those are two
> > different panels or a single panel with slight difference in the glass
> > cover. With these names in place (well, with two distinct names in
> > place) it makes sense.
>
> For completeness: keep the current single file but embed these panel
> names as suffix (eg. `samsung,sofef-01-m-am[bs]...`) to the compatible
> (and document these more explicitly elsewhere)?

Where do the sofef parts of the name come from? Glancing at other 
panels, I'd expect something simpler. Maybe:

samsung,sofef01m-amb60...

> - Marijn
>
> > --
> > With best wishes
> > Dmitry

--
With best wishes
Dmitry