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    SubjectRe: [PATCH 2/2] mtd: orion-nand: fix build error with ARMv4
    On 09 May 03:28 PM, Jason Gunthorpe wrote:
    >
    > > I gave this a try in order to answer Arnd's performance
    > > question. First of all, the patch seems wrong. I guess it's because
    > > readsl reads 4-bytes pieces, instead of 8-bytes.
    > >
    > > This patch below is tested (but not completely, see below) and works:
    >
    > Compilers are better now, I think you can just ditch the weirdness:
    >
    [..]
    >
    > The below gives:
    >
    > c8: ea000002 b d8 <orion_nand_read_buf+0x84>
    > cc: e5dc0000 ldrb r0, [ip]
    > d0: e7c30001 strb r0, [r3, r1]
    > d4: e2811001 add r1, r1, #1
    > d8: e1510002 cmp r1, r2
    >
    > Which looks the same as the asm version to me.
    >

    Nice! It wasn't really needed but since I have the board here:

    # 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"

    --
    Ezequiel García, Free Electrons
    Embedded Linux, Kernel and Android Engineering
    http://free-electrons.com
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