Re: [PATCH 0/2] drm: add SimpleDRM driver

Daniel Vetter
2016-08-04T15:08:49Z

On Thu, Aug 04, 2016 at 04:15:25PM +0200, Luc Verhaegen wrote:
> On Thu, Aug 04, 2016 at 04:03:18PM +0200, Noralf Trønnes wrote:
> >
> > I have tested simpledrm on a Raspberry Pi B+ with U-boot setting up the
> > framebuffer and producing this node:
> >
> > framebuffer@1e887000 {
> > compatible = "simple-framebuffer";
> > reg = <0x1e887000 0x36c600>;
> > format = "r5g6b5";
> > width = <1824>;
> > height = <984>;
> > stride = <3648>;
> > status = "okay";
> > };
> >
> > I have only tested with fbcon and modetest (XR24,RG16).
>
> Please do not make the same mistake as simplefb in making this purely a
> rpifb. Know that you will need some power and clock management for
> properly free devices that do not depend on a binary only RTOS which
> does _everything_ behind our backs.
>
> Cfr this useless, endless and ridiculous discussion:
> http://lists.infradead.org/pipermail/linux-arm-kernel/2014-August/279071.html

simpledrm isn't a real driver, but only meant to be used to drive the
firmware framebuffer in early boot until a real driver takes over. It's a
replacement really for all the various uefi/vesa/whatever fbdev drivers.
Full reliance on the firmware very much intended.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation