Re: Bug 205201 - Booting halts if Dawicontrol DC-2976 UW SCSI board installed, unless RAM size limited to 3500M

[Christian Zigotzky]

On 27 November 2019 at 07:56 am, Mike Rapoport wrote:
> Maybe we'll simply force bottom up allocation before calling
> swiotlb_init()? Anyway, it's the last memblock allocation.
>
>
> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
> index 62f74b1b33bd..771e6cf7e2b9 100644
> --- a/arch/powerpc/mm/mem.c
> +++ b/arch/powerpc/mm/mem.c
> @@ -286,14 +286,15 @@ void __init mem_init(void)
>   	/*
>   	 * book3s is limited to 16 page sizes due to encoding this in
>   	 * a 4-bit field for slices.
>   	 */
>   	BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
>   
>   #ifdef CONFIG_SWIOTLB
> +	memblock_set_bottom_up(true);
>   	swiotlb_init(0);
>   #endif
>   
>   	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
>   	set_max_mapnr(max_pfn);
>   	memblock_free_all();
>   
>   
Hello Mike,

I tested the latest Git kernel with your new patch today. My PCI TV card 
works without any problems.

Thanks,
Christian