Re: [linux-sunxi] Re: [PATCH v10 04/11] drm/sun4i: tcon: Compute DCLK dividers based on format, lanes

[Jagan Teki]

On Tue, Jul 2, 2019 at 8:59 PM Maxime Ripard <maxime.ripard@xxxxxxxxxxx> wrote:
>
> On Tue, Jul 02, 2019 at 12:30:14AM +0530, Jagan Teki wrote:
> > On Tue, Jun 25, 2019 at 8:07 PM Maxime Ripard <maxime.ripard@xxxxxxxxxxx> wrote:
> > > > > > > > > > BSP has tcon_div and dsi_div. dsi_div is dynamic which depends on
> > > > > > > > > > bpp/lanes and it indeed depends on PLL computation (not tcon_div),
> > > > > > > > > > anyway I have explained again on this initial link you mentioned.
> > > > > > > > > > Please have a look and get back.
> > > > > > > > >
> > > > > > > > > I'll have a look, thanks.
> > > > > > > > >
> > > > > > > > > I've given your patches a try on my setup though, and this patch
> > > > > > > > > breaks it with vblank timeouts and some horizontal lines that looks
> > > > > > > > > like what should be displayed, but blinking and on the right of the
> > > > > > > > > display. The previous ones are fine though.
> > > > > > > >
> > > > > > > > Would you please send me the link of panel driver.
> > > > > > >
> > > > > > > It's drivers/gpu/drm/panel/panel-ronbo-rb070d30.c
> > > > > >
> > > > > > Look like this panel work even w/o any vendor sequence. it's similar
> > > > > > to the 4-lane panel I have with RGB888, so the dclk div is 6, is it
> > > > > > working with this divider?
> > > > >
> > > > > It works with 4, it doesn't work with 6.
> > > >
> > > > Can be the pixel clock with associated timings can make this diff.
> > > > Would you send me the pixel clock, pll_rate and timings this panel
> > > > used it from BSP?
> > >
> > > This board never had an Allwinner BSP
> >
> > Running on BSP would help to understand some clue, anyway would you
> > send me the the value PLL_MIPI register (devme 0x1c20040) on this
> > board. I'm trying to understand how it value in your case.
>
> I'm sorry, but I'm not going to port a whole BSP on that board,
> especially for something I haven't been convinced it's the right fix.

Look like a dead lock here, this change has a conclusive evidence from
BSP (which is AW datasheet or open code to outside world) and it is
working with A33, A64 and R40 which was tested in 4 different panels
and I don't understand the reason for not going with this (atleast
check with respect to BSP).

Please suggest, what I can do further, your suggestion is very helpful here.

Jagan.