The new value for yoffset is passed by the user space component
(library/process or what not???) to the fb layer through a
fb_pan_display call and which in-turn would be redirected to the
omap_fb layer.

Warm Regards,
Anil

On Wed, Jun 18, 2008 at 11:46 AM, Marty <[EMAIL PROTECTED]> wrote:
>
> Dear Anil,
>
> Thanks for your reply. After reading your reply, I can understand it
> more.
> So that, the value of start address is changed by calling function -
> "user space graphics library", not "omap fb driver" itself.
>
> Is it correct?
>
> Thank you a lot !!!
>
> Best Regards,
> Marty
>
> On 6月18日, 下午1時02分, "Anil Sasidharan" <[EMAIL PROTECTED]> wrote:
>> Hello Matry,
>>
>>
>>
>> > BTW, in patched omapfb_main.c, I just can see the y_virtual is doubled
>> > for page flipping.
>> > However, I can't find the code that change the pointer to switch the
>> > start address of FB between 2 FBs.
>>
>>       The user space graphics library (I guess its Surfaceflinger in
>> Android), calls the generic "fb_pan_display" with 2 different values
>> of "yoffset" for every alternative invocation (ex: value "0" for the
>> odd invocation and value "480" for even invocation). This routine
>> would in-turn call the "omapfb_pan_display" and that would invoke
>> "ctrl_change_mode" function with the given "yoffset". This function
>> would compute and switch the pointer to the new start address of the
>> fb based on the updated "yoffset" and calls the "setup_plane" function
>> of the display controller (pls refer dispc.c under drivers/video/omap
>> directory ) and rest is history!!
>>
>> Hope this may answer your question.
>>
>> Warm Regards,
>> Anil
>>
>>
>>
>>
>>
>> > Thank you!!!- 隱藏被引用文字 -
>>
>> - 顯示被引用文字 -
> >
>

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