[U-Boot] [PATCH 02/10] mx23: Document the tRAS lockout setting in memory initialization

Marek Vasut
2013-01-30T14:10:59Z

Dear Otavio Salvador,

> Add a comment about the tRAS lockout setting of HW_DRAM_CTL08 to
> enable the 'Fast Auto Pre-Charge' found in the memory chip. The
> setting is applied after memory initialization and it is worth
> document it.
>
> Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
> ---
> arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c
> b/arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c index f8392f6..37b50e9 100644
> --- a/arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c
> +++ b/arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c
> @@ -119,6 +119,7 @@ static void initialize_dram_values(void)
> writel(dram_vals[i], MXS_DRAM_BASE + (4 * i));
>
> #ifdef CONFIG_MX23
> + /* Enable tRAS lockout in HW_DRAM_CTL08 */

This does not explain why it must be here and not in the dram_vals table. It
would be nice to explain it here, since it'd prevent others from sending patch
stuffing it into the dram_vals table without knowing it must definitelly be
here.

But why does it have to be here? I wonder ...

> writel((1 << 24), MXS_DRAM_BASE + (4 * 8));
> #endif
> }

Best regards,
Marek Vasut