Re: [5.17 regression] "x86/PCI: Ignore E820 reservations for bridge windows on newer systems" breaks suspend/resume

[Mika Westerberg]

Hi Hans,

On Wed, Feb 09, 2022 at 05:08:13PM +0100, Hans de Goede wrote:
> As mentioned in my email from 10 seconds ago I think a better simpler
> fix would be to just do:
> 
> diff --git a/arch/x86/kernel/resource.c b/arch/x86/kernel/resource.c
> index 9b9fb7882c20..18656f823764 100644
> --- a/arch/x86/kernel/resource.c
> +++ b/arch/x86/kernel/resource.c
> @@ -28,6 +28,10 @@ static void remove_e820_regions(struct resource *avail)
>  	int i;
>  	struct e820_entry *entry;
>  
> +	/* Only remove E820 reservations on classic BIOS boot */
> +	if (efi_enabled(EFI_MEMMAP))
> +		return;
> +
>  	for (i = 0; i < e820_table->nr_entries; i++) {
>  		entry = &e820_table->entries[i];
>  
> 
> I'm curious what you think of that?

I'm not an expert in this e820 stuff but this one looks really simple
and makes sense to me. So definitely should go with it assuming there
are no objections from the x86 maintainers.