Re: simple framebuffer slower by factor of 20, on socfpga (arm) platform

From: Pavel Machek
Date: Fri Apr 24 2015 - 09:31:37 EST

> > The difference is probably caused by memcpy() vs memcpy_fromio(). The
> > comment above memcpy_fromio() says "This needs to be optimized". I think
> > generally speaking memcpy_fromio() is correct for a framebuffer.
> >
> > That said, if the fb is in RAM, and is only written by the CPU, I think
> > a normal memcpy() for fb_memcpy_fromfb() should be fine...
> Could memcpy() cause alignment traps here if the fb pointer is unaligned
> and uncached?

Original commit did not comment on any failure, so I expect that is
not a problem here...
(cesky, pictures)
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