Re: [PATCH 0/2] MMC discard support (was [PATCH 0/7] Discard requests, v2)

[Pierre Ossman <drzeus-list@drzeus.cx>]

[-- Attachment #1: Type: text/plain, Size: 1098 bytes --]

On Sat, 23 Aug 2008 08:59:11 +0900
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> wrote:

> Pierre Ossman <drzeus-list@drzeus.cx> writes:
> >
> > I have tried those two and others, and I cannot see any noticeable
> > difference in performance. Please perform your own tests though as I
> > might have overlooked something.
> 
> I see, sounds like erase commands of sd/mmc was ignored.

If only. :)

The device does take some time to perform the command, and the data is
indeed gone after the command has completed. So there is no doubt that
the sector gets erased.

It might simply be that so few (no?) SD/MMC readers actually implement
these commands, so the card vendors haven't bothered implementing any
decent handling of them.

-- 
     -- Pierre Ossman

  Linux kernel, MMC maintainer        http://www.kernel.org
  rdesktop, core developer          http://www.rdesktop.org

  WARNING: This correspondence is being monitored by the
  Swedish government. Make sure your server uses encryption
  for SMTP traffic and consider using PGP for end-to-end
  encryption.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 197 bytes --]