Re: [PATCH 2/2] mtd: orion-nand: fix build error with ARMv4

[Ezequiel Garcia]

On 10 May 12:24 AM, Arnd Bergmann wrote:
> On Friday 09 May 2014 19:09:15 Ezequiel Garcia wrote:
> > # time nanddump /dev/mtd5 -f /dev/null -q
> > real    0m 5.82s
> > user    0m 0.20s
> > sys     0m 5.60s
> > 
> > Jason: Care to submit a proper patch?
> > 
> > On 08 May 04:56 PM, Arnd Bergmann wrote:
> > > Ok, that is a noticeable difference. For scale, what is the size of that partition?
> > 
> > The board is Openblocks A6, running mainline.
> > 
> > # cat /proc/mtd 
> > dev:    size   erasesize  name
> > mtd0: 00090000 00004000 "uboot"
> > mtd1: 00044000 00004000 "env"
> > mtd2: 00024000 00004000 "test"
> > mtd3: 00400000 00004000 "conf"
> > mtd4: 01d20000 00004000 "linux"
> > mtd5: 01dec000 00004000 "user"
> 
> Ok, so it takes 5.6 seconds in kernel mode to access 31MB, which comes down
> to 5.60MB/s. That isn't very fast compared to the time the CPU should take
> for those instructions, so I'm surprised it actually makes any difference
> at all.
>
> There isn't a usable slave DMA engine in Armada XP by chance?
> 

The Openblocks A6 is a Kirkwood, not Armada XP.
-- 
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com
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