[lkml]   [2015]   [Mar]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 3/3] e820: Add the unknown-12 Memory type (DDR3-NvDIMM)
On Thu, Mar 5, 2015 at 2:24 AM, Boaz Harrosh <> wrote:
> There are multiple vendors of DDR3 NvDIMMs out in the market today.
> At various stages of development/production. It is estimated that
> there are already more the 100ds of thousands chips sold to
> testers and sites.
> All the BIOS vendors I know of, tagged these chips at e820 table
> as type-12 memory.
> Now the ACPI comity, as far as I know, did not yet define a
> standard type for NvDIMM. Also, as far as I know any NvDIMM
> standard will only be defined for DDR4. So DDR3 NvDIMM is
> probably stuck with this none STD type.

There's no relation between E820 types and DDR technology revisions.

> I Wish and call the ACPI comity to Define that NvDIMM is type-12.
> Also for DDR4
> The motivation of this patch is to be able to differentiate
> this NvDIMM type from a real future "unknown-reserved" type.
> In this patch I name type-12 "unknown-12". This is because of
> ACPI politics that refuse to reserve type-12 as DDR3-NvDIMM

It's not "politics". Setting standards takes time and the platforms
in question simply jumped the gun to enable a proof-of-concept.

> and members keep saying:
> "What if ACPI assigns type-12 for something else in future"
> [And I say: Then just don't. Please?]

Once a standard number is assigned, platform firmwares can update
type-12 to that number. We might consider a compile time override for
these niche/pre-standard systems that can't/won't update, but it's not
clear to me that we even need to go that far.

 \ /
  Last update: 2015-03-05 22:01    [W:0.164 / U:0.104 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site