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

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 [off-list ref] wrote:

quoted

Hi Ajay,

On Tue, Sep 20, 2011 at 11:30:39AM -0400, Ajay Kumar wrote:

quoted

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]

quoted

+/* 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

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