Re: [PATCH] arm: imx: mmdc_size: Increase row_max for imx8m

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Hello,

On 20.05.22 16:23, Teresa Remmet wrote:
> As DDRC_ADDRMAP7_ROW_B16 and DDRC_ADDRMAP7_ROW_B17 are used
> now for the row size calculation we need to increase row_max to 18.
> 
> For LPDDR4 this only works in combination with ram timings
> created with recent configuration spreadsheet versions.
> With older versions the register DDRC_ADDRMAP7 may not be set and
> calculation will lead to wrong results even with this patch.
> 
> Fixes: dad2b5636bd8 ("ARM: imx: Add imx8 support for 18 bit SDRAM row size handle")
> Signed-off-by: Teresa Remmet <t.remmet@phytec.de>

I have an out-of-tree i.MX8MM board with LPDDR4 that reported a correct size of 1G
prior to this patch and now it reports 4G. DDRC_ADDRMAP7 is not explicitly initialized,
but it's being read as zero, so the calculation seems to still be broken..

> ---
>  arch/arm/mach-imx/esdctl.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-imx/esdctl.c b/arch/arm/mach-imx/esdctl.c
> index 8dd0ddbbc965..b070ebc62a45 100644
> --- a/arch/arm/mach-imx/esdctl.c
> +++ b/arch/arm/mach-imx/esdctl.c
> @@ -488,7 +488,7 @@ static resource_size_t imx8m_ddrc_sdram_size(void __iomem *ddrc)
>  
>  	return imx_ddrc_sdram_size(ddrc, addrmap,
>  				   12, ARRAY_AND_SIZE(col_b),
> -				   16, ARRAY_AND_SIZE(row_b),
> +				   18, ARRAY_AND_SIZE(row_b),
>  				   reduced_adress_space, true);
>  }
>  


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