Re: [PATCH v3 3/3] console/fbcon: Add support for deferred console takeover

[Hans de Goede]

Hi,

On 26-06-18 19:12, Andy Shevchenko wrote:
> On Tue, Jun 26, 2018 at 4:55 PM, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
> > Currently fbcon claims fbdevs as soon as they are registered and takes over
> > the console as soon as the first fbdev gets registered.
> >
> > This behavior is undesirable in cases where a smooth graphical bootup is
> > desired, in such cases we typically want the contents of the framebuffer
> > (typically a vendor logo) to stay in place as is.
> >
> > The current solution for this problem (on embedded systems) is to not
> > enable fbcon.
> >
> > This commit adds a new FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER config option,
> > which when enabled defers fbcon taking over the console from the dummy
> > console until the first text is displayed on the console. Together with the
> > "quiet" kernel commandline option, this allows fbcon to still be used
> > together with a smooth graphical bootup, having it take over the console as
> > soon as e.g. an error message is logged.
>
> > +       for (i = 0; i < FB_MAX; i++) {
> > +               if (registered_fb[i])
> > +                       fbcon_fb_registered(registered_fb[i]);
> > +       }
>
> Simple git grep shows that we perhaps do
>
> #define for_each_registered_fbcon(i) ...
>
> (As an example see for_each_pci_bridge() how it's done there)

This is probably a worthwhile cleanup for all the fbdev related
code / drivers. But outside of the scope of this patchset.

Regards,

Hans