[Intel-gfx] [PATCH] drm/i915/mtl: Connect root sysfs entries to GT0

[Dixit, Ashutosh]

On Thu, 12 Jan 2023 18:27:52 -0800, Vinay Belgaumkar wrote:
>
> Reading current root sysfs entries gives a min/max of all
> GTs. Updating this so we return default (GT0) values when root
> level sysfs entries are accessed, instead of min/max for the card.
> Tests that are not multi GT capable will read incorrect sysfs
> values without this change on multi-GT platforms like MTL.
>
> Fixes: a8a4f0467d70 ("drm/i915: Fix CFI violations in gt_sysfs")

We seem to be proposing to change the previous sysfs ABI with this patch?
But even then it doesn't seem correct to use gt0 values for device level
sysfs. Actually I received the following comment about using max freq
across gt's for device level freq's (gt_act_freq_mhz etc.) from one of our
users:

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On Sun, 06 Nov 2022 08:54:04 -0800, Lawson, Lowren H wrote:

Why show maximum? Wouldn’t average be more accurate to the user experience?

As a user, I expect the ‘card’ frequency to be relatively accurate to the
entire card. If I see 1.6GHz, but the card is behaving as if it’s running a
1.0 & 1.6GHz on the different compute tiles, I’m going to see a massive
decrease in compute workload performance while at ‘maximum’ frequency.
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So I am not sure why max/min were previously chosen. Why not the average?

Thanks.
--
Ashutosh