RE: LS1021A performance

[Renaud Barbier <Renaud.Barbier@ametek.com>]

> > > Can you compare SHA256 instead and see if the difference is still as stark?
> > > Make sure that CONFIG_DIGEST_SHA256_ARM is enabled.
> > The SHA256 is enabled. SHA256 on a 1 MB file:
> > Barebox: 843ms
> > Linux:
> > [root@openware]# time sha256sum /tmp/mtd0
> > eef67a3327e3eaa50ee7b1dad87901465f00d76a6308e360a2fedab82c79f493
> > /tmp/mtd0
> >
> > real    0m0.059s
> > user    0m0.056s
> > sys     0m0.001s
> >
> > On another note, the boot loader using the LS1021A is much slower than
> using the PPC P1014.
> > I compare those two as we used the LS1021A as a replacement for P1014
> > on a board (same peripherals, same boot sequence) The P1014 reach the
> prompt in 200ms while the LS1021 takes 700ms.
> >
> > Also, I noticed that the pageflags is different for the DDR memory on
> Barebox and Linux as seen by the Lauterbach:
> > Barebox: write-back/no allocate
> > Linux : Inner:write-back/allocate outer: write-back/allocate Could
> > that mean the L2 cache Is not used?
> > >
> > > Do barebox and Linux run at the same CPU frequency?
> > According to the Lauterbach, clock ratio have not changed in the
> > clocking registers
> > >
> 
> As the LS1021A is based on a Cortex A7 your board lowlevel init needs to call
> cortex_a7_lowlevel_init() for the caches to work properly.
> 
> It's probably a good idea to add a ls1021 lowlevel init function which calls both
> of those functions together, like imx6ul_cpu_lowlevel_init().
> 

With this function call, the boot loader boots 3 times faster and sha256sum for 1MB dropped to 118ms from 843ms
This now breaks the gianfar Ethernet driver which likely needs cache flush or dma allocated descriptors.

Thanks.