[PATCH v5] drm/mcde: Some fixes to handling video mode

[Linus Walleij]

On Tue, Dec 17, 2019 at 11:27 AM Stephan Gerhold <stephan at gerhold.net> wrote:

> I feel kind of bad to keep requesting changes for this patch,

Don't feel like that. It is complex hardware and complex code,
so it leads to complex development.

Also I am making way too many stupid mistakes :/

> > +             val = readl(d->regs + DSI_VID_PCK_TIME);
> > +             val &= ~DSI_VID_PCK_TIME_BLKEOL_DURATION_MASK;
> > +             val |= blkeol_duration <<
> > +                     DSI_VID_PCK_TIME_BLKEOL_DURATION_SHIFT;
> > +             writel(val, d->regs + DSI_VID_PCK_TIME);
> > +
> > +             /* Max burst limit, this is given in bytes */
> > +             val = readl(d->regs + DSI_VID_VCA_SETTING1);
> > +             val &= ~DSI_VID_VCA_SETTING1_MAX_BURST_LIMIT_MASK;
> > +             val |= blkeol_duration - 6;
>
> The vendor kernel writes blkeol_pck - 6 (instead of blkeol_duration) here:
>
> dsi_wfld(io, DSI_VID_VCA_SETTING1, MAX_BURST_LIMIT, vid_regs->blkeol_pck - 6);

You're right, and still I read the code over and over...
It's good we have 2 pairs of eyes.

> Also: It does not make a functional difference here but for clarity we
> should shift the value by DSI_VID_VCA_SETTING1_MAX_BURST_LIMIT_SHIFT (= 0),
> i.e.
>
> val |= blkeol_pck - 6 << DSI_VID_VCA_SETTING1_MAX_BURST_LIMIT_SHIFT;

OK I fix!

Yours,
Linus Walleij