[PATCH 03/11] Bring in dynamic videomode selection at runtime
jbe at pengutronix.de
Sat Oct 23 06:35:07 EDT 2010
Sascha Hauer wrote:
> On Fri, Oct 22, 2010 at 06:53:17PM +0200, Juergen Beisert wrote:
> > This patch mostly rewrites all parts of /drivers/video/fb.c. As it
> > changes the API to the drivers, it must be done in one step to keep the
> > repository bisectable. But to do it in one step makes the patches itself
> > unreadable.
> > So, I decided to do it in a few steps, only for the review. All patches
> > marked with a "step n of m" should be merged, prior the final commit into
> > the repository.
> > This step brings in the required functions for dynamic videomode
> > selection at runtime, but keep the old functions untouched (the new ones
> > are commented out).
> > This is patch 1 of 7 to keep the repository bisectable.
> > Signed-off-by: Juergen Beisert <jbe at pengutronix.de>
> > ---
> > drivers/video/Kconfig | 23 +++++
> > drivers/video/fb.c | 251
> > +++++++++++++++++++++++++++++++++++++++++++++++++ include/fb.h |
> > 40 ++++++++
> > 3 files changed, 314 insertions(+), 0 deletions(-)
> > diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
> > index 7a89a3f..e6ecfc8 100644
> > --- a/drivers/video/Kconfig
> > +++ b/drivers/video/Kconfig
> > @@ -5,6 +5,29 @@ menuconfig VIDEO
> > if VIDEO
> > +comment "runtime options"
> > +
> > +config VIDEO_DELAY_ENABLING
> > + bool "Delayed enabling"
> > + help
> > + Say 'y' here to delay enabling video output. This is useful to first
> > + fill the framebuffer (splash screen for example) prior enabling the
> > + video device.
> > + This entry adds the "enable" parameter to the video device, to
> > enable + or disable video output at runtime.
> > +
> > +config VIDEO_DELAY_INIT
> > + bool "Delayed initialization"
> > + select VIDEO_DELAY_ENABLING
> > + help
> > + If the platform supports more than one video mode say 'y' her to
> > delay + the initialization of the video device until any kind of
> > barebox's + shell code sets up the correct mode at runtime.
> > + This entry adds the "mode" parameter to the video device, to
> > setup + the desired videomode prior enabling it at runtime.
> I think the framebuffers should *never* be activated by the setup code
> and should be explicitely initialized by doing a 'fb0.enable=1' on the
> command line.
Okay. It "should not" is a new policy to barebox. Currently the framebuffer is
activated immediately (except the platforms you changed already). I just
wanted to keep this behaviour.
> This way we have the most flexibility. We can enable
> the framebuffer when we actually need it, we can draw a splash screen
> before enabling it so that we do not have a black screen before we draw
> an image. Also, the environment can decide to leave the framebuffer
> disabled because the kernel will draw another screen a second later. If
> necessary, the environemt can do a fb0.display="sharp-whatever" before
> activating it. And we do not need any kconfig options for this.
Okay. We can change the default behaviour for all platforms using graphic in
this way. I will try to include it in the next series.
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