[U-Boot] [PATCH] EXYNOS: SMDK5250: Add support for DDR3 memory.

[Doug Anderson]

On Wed, Feb 8, 2012 at 3:44 AM, Hatim Ali <hatim.rv at samsung.com> wrote:
> SMDK5250 development boards have different memory variants like
> DDR3, LPDDR2 and LPDDR3. This patch adds supports for DDR3.
> The DDR3 is configured for 667Mhz and is being enabled by default.

One other note: the SDRAM doesn't appear to be stable with the current
CL as is.  Specifically, I ran this test:

Load two copies of vmlinuz:

 Hit any key to stop autoboot:  0
 SMDK5250 # mmc rescan 0
 SMDK5250 # fatload mmc 0:c 0x42000000 vmlinuz
 reading vmlinuz

 3272888 bytes read
 SMDK5250 # fatload mmc 0:c 0x40008000 vmlinuz
 reading vmlinuz

 3272888 bytes read

Now compare them:

 SMDK5250 # cmp.l 0x40008000 0x42000000 3272888
 word at 0x400097fc (0xe3160024) != word at 0x420017fc (0xe3160020)
 Total of 1535 words were the same

...but if you look at that memory, it's the same!

 SMDK5250 # md.l 0x420017fc 1
 420017fc: e3160020     ...
 SMDK5250 # md.l 0x400097fc 1
 400097fc: e3160020     ...

...in this case, re-running the cmp.l still showed the difference (?)


Running RAM at 400MHz didn't show the same problem.  NOTE: that
doesn't prove the the problem is related to SDRAM stability, but it
sure looks suspicious.

-Doug