Re: [PATCH] x86, microcode, Fix long microcode load time when firmwarefile is missing [v2]

From: Prarit Bhargava
Date: Mon Oct 28 2013 - 11:11:40 EST




On 10/28/2013 11:06 AM, Henrique de Moraes Holschuh wrote:
> On Mon, 28 Oct 2013, Borislav Petkov wrote:
>> So Prarit, please split this patch into changes which *directly* address
>> the issue and other cleanups ontop. This will simplify review immensely
>> as having one single bulky patch is not easy on the eyes.
>>
>> Then, make sure to audit the lowlevel drivers whether they're already
>> issuing output on the error path before adding new printks arbitrarily.
>
> Something else I couldn't check just from the description (and I apologise,
> but I did not look at your patch closely enough to check how you implemented
> the functionality on Intel): in the general case, it is NOT acceptable to
> bail out if you cannot find the firmware for the first processor.
> Mixed-stepping systems do exist, and you might need to update the microcode
> of, e.g, just the third processor.
>
> AMD can get away with a half-done implementation of negative caching (or an
> "optimised one" depending on your PoV :) ) because they have per-family
> firmware files, so even mixed-stepping systems will require only the same
> file. This is *not* true for Intel, which is really annoying.

Is that right? :( I took Andi's comment to imply otherwise ... If that's the
case then, yeah, back to the drawing board with this.

Andi (or anyone from Intel) -- care to offer a comment?

P.
>
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