linux-kernel - Re: [PATCH v4 1/4] RAS/AMD/ATL: Read DRAM hole base early

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Date: Tue, 28 May 2024 10:16:59 +0200
From: Borislav Petkov <bp@...en8.de>
To: John Allen <john.allen@....com>
Cc: linux-edac@...r.kernel.org, tony.luck@...el.com, yazen.ghannam@....com,
	linux-kernel@...r.kernel.org, avadhut.naik@....com,
	muralidhara.mk@....com
Subject: Re: [PATCH v4 1/4] RAS/AMD/ATL: Read DRAM hole base early

On Mon, May 06, 2024 at 03:46:02PM +0000, John Allen wrote:
> @@ -282,6 +298,11 @@ int get_df_system_info(void)
>  
>  	get_num_maps();
>  
> +	if (get_dram_hole_base()) {
> +		pr_warn("amd_atl: Failed to read DRAM hole base");

This thing with the printk prefix "amd_atl: ". Please do a pre-patch
which adds

#undef pr_fmt
#define pr_fmt(fmt) "amd_atl: " fmt

to ...atl/internal.h and remove all such string prefixes from the pr_*
statements in the driver.

> +		return -EINVAL;

So this basically says that the driver won't load if it can't read hole
base. But it did load before - on failure to read that reg, it would
simply fail translating.

So why is that failure so tragic? Or is it that we absolutely need hole
base in all circumstances so that loading it is pointless if not?

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette