[PATCH 3/5] video: Use cyclic to handle video sync

[Simon Glass]

Hi Tom,

On Sun, 19 Nov 2023 at 08:59, Tom Rini <trini at konsulko.com> wrote:
>
> On Sun, Nov 19, 2023 at 07:46:41AM -0700, Simon Glass wrote:
> > At present U-Boot flushes the cache after every character written to
> > ths display. This makes the command-line slower, to the point that
> > pasting in long strings can fail.
> >
> > Add a cyclic function to sync the display every 10ms. Enable this by
> > default.
> >
> > Allow much longer times for sandbox, since the SDL display is quite
> > slow.
> >
> > Avoid size growth if the feature is disabled by making the new init and
> > destroy functions dependent on CYCLIC being enabled.
> >
> > Signed-off-by: Simon Glass <sjg at chromium.org>
> > ---
> >
> >  drivers/video/Kconfig        | 30 +++++++++++++++++++++++
> >  drivers/video/video-uclass.c | 46 ++++++++++++++++++++++++++++++++----
> >  2 files changed, 72 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
> > index 6f319ba0d544..1742e342f466 100644
> > --- a/drivers/video/Kconfig
> > +++ b/drivers/video/Kconfig
> > @@ -7,6 +7,7 @@ menu "Graphics support"
> >  config VIDEO
> >       bool "Enable driver model support for LCD/video"
> >       depends on DM
> > +     imply CYCLIC
> >       help
> >         This enables driver model for LCD and video devices. These support
> >         a bitmap display of various sizes and depths which can be drawn on
>
> We should at least expand the help message to say that if you enable
> cyclic you get some other behavior. In hind sight, cyclic shouldn't be
> prompted and it should be selected as used. But that's not an issue for
> this patch set.

Yes it is similar to EVENT I think. But note that some boards do use
it for other purposes.

I assume you mean to expand the help for VIDEO

Regards,
Simon