Re: [PATCH v2] ARM: mvebu: Warn about memory chunks too small for DDR training

[Gregory CLEMENT <gregory.clement@bootlin.com>]

Hi Uwe,

> For each memory region the first 10K are reserved for DDR training. Emit
> a warning if the area happens to be smaller than these 10K. This should
> not happen, but if it does this message simplifies diagnosing the
> problem.
>
> This fixes a W=1 compiler error:
>
> 	arch/arm/mach-mvebu/board-v7.c: In function ‘mvebu_scan_mem’:
> 	arch/arm/mach-mvebu/board-v7.c:84:27: error: variable ‘size’ set but not used [-Werror=unused-but-set-variable]
> 	   84 |                 u64 base, size;
> 	      |                           ^~~~
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>

Applied on mvebu/arm

Thanks,

Gregory
> ---
> Hello,
>
> the (implicit) first iteration of this patch is available at
> https://lore.kernel.org/linux-arm-kernel/20240708093145.1398949-2-u.kleine-koenig@baylibre.com/
>
> In this v2 the size variable is evaluated to emit a warning instead of
> being dropped, which was done in v1.
>
> Best regards
> Uwe
>
>  arch/arm/mach-mvebu/board-v7.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/arch/arm/mach-mvebu/board-v7.c b/arch/arm/mach-mvebu/board-v7.c
> index fd5d0c8ff695..04ad651d13a0 100644
> --- a/arch/arm/mach-mvebu/board-v7.c
> +++ b/arch/arm/mach-mvebu/board-v7.c
> @@ -86,6 +86,9 @@ static int __init mvebu_scan_mem(unsigned long node, const char *uname,
>  		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
>  		size = dt_mem_next_cell(dt_root_size_cells, &reg);
>  
> +		if (size < MVEBU_DDR_TRAINING_AREA_SZ)
> +			pr_warn("Too little memory to reserve for DDR training\n");
> +
>  		memblock_reserve(base, MVEBU_DDR_TRAINING_AREA_SZ);
>  	}
>  
> -- 
> 2.43.0