[PATCH 1/3] include: fb: Add definiton for window positioning structure

Baruch Siach
2011-09-20T17:08:59Z

Hi Ajay,

On Tue, Sep 20, 2011 at 08:56:57PM +0530, Ajay kumar wrote:
> Hi Baruch,
> On Tue, Sep 20, 2011 at 4:54 PM, Baruch Siach <baruch@tkos.co.il> wrote:
> > Hi Ajay,
> >
> > On Tue, Sep 20, 2011 at 11:30:39AM -0400, Ajay Kumar wrote:
> >> This patch adds a data structure definiton to hold framebuffer windows/planes.
> >> An ioctl number is also added to provide user access
> >> to change window position dynamically.
> >
> > [snip]
> >
> >> +/* Window overlaying */
> >> +struct fb_overlay_win_pos {
> >> + ? ? __u32 win_pos_x; ? ? ? ?/* x-offset from LCD(0,0) where window starts */
> >> + ? ? __u32 win_pos_y; ? ? ? ?/* y-offset from LCD(0,0) where window starts */
> >> +};
> >
> > Why not allow negative offsets where the left or upper part of the framebuffer
> > is hidden?
>
> Thanks for pointing it out. Are there drivers which place the overlay
> windows such that some part of the window is hidden from being
> displayed on the screen?

I don't know. However, since this is new userspace ABI which should stay
compatible forever, we should make sure to do it right. Using __s32 instead of
__u32 won't limit us in the future.

baruch

--
~. .~ Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
- baruch at tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -