question about ephyrPreparePipelinedAccess() in ephyr_draw.c

[Dodji Seketeli]

Hello,

In hw/kdrive/ephyr/ephyr_draw.c, in 
ephyrPreparePipelinedAccess(), I am not sure to understand what this
line does:

pPix->devPrivate.ptr = fakexa->exa->memoryBase +
exaGetPixmapOffset(pPix);

I think it hides (caches) the offset (within framebuffer memory) of the
beginning of pPix, so that subsequent calls to exaGetPixmapOffset(pPix)
return that recently cached offset.

But why is that necessary, since the function
unsigned long exaGetPixmapOffset(PixmapPtr pPix); returns that offset
even if it has not be cached before ?

Thank you in advance.

-- 
Dodji Seketeli
http://www.seketeli.org/dodji