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    Subject[PATCH] powerpc 4xx: DDR0_14[REDUC] decoded incorrectly
    Hi,

    according to the PPC440EPx Embedded Processor User Manual (rev 1.14)
    DDR0_14[REDUC] bit has the following meaning:

    REDUC - Enable the half data path feature of the controller
    0 = Standard operation using full 64/72-bit memory bus
    1 = Memory data path width is 32/40 bits

    However, "1" is decoded as 64 bit (8 byte), "0" - as 32 bit (4 byte) bus
    by the kernel code. My understanding is this is not correct - patch
    attached.


    --- linux.orig/arch/powerpc/boot/4xx.c 2009-03-09 17:55:01.000000000 +0200
    +++ linux/arch/powerpc/boot/4xx.c 2009-03-09 17:58:07.000000000 +0200
    @@ -193,9 +193,9 @@
    val = SDRAM0_READ(DDR0_14);

    if (DDR_GET_VAL(val, DDR_REDUC, DDR_REDUC_SHIFT))
    - dpath = 8; /* 64 bits */
    - else
    dpath = 4; /* 32 bits */
    + else
    + dpath = 8; /* 64 bits */

    /* get address pins (rows) */
    val = SDRAM0_READ(DDR0_42);
    \
     
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      Last update: 2009-03-09 17:39    [W:0.030 / U:30.084 seconds]
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