Re: [PATCH] MMC updates

[Russell King <rmk+lkml@arm.linux.org.uk>]

On Tue, Aug 31, 2004 at 08:27:14AM +0200, Pierre Ossman wrote:
> Russell King wrote:
> >For anyone who's interested, here's an update to the MMC code Linus
> >recently merged.  Essentially, I've added SG support to the MMCI
> >primecell driver.
>
> Just to make sure I've understood this correctly. SGIO takes a number of 
> memory locations and fills these with data from a continous stream of 
> data from the card? I.e. only the local memory locations need special 
> handling. No seeking on the card? And any "gaps" where data is not 
> wanted is handled by upper layers?

Correct.  One "request" is for a set of sectors from N to N+L, where
data is read/written to a set of possibly non-contiguous pages.

You don't have to support it - there are defaults chosen by the code
to ensure that we won't see these "SG" requests unless the driver can
handle them.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 PCMCIA      - http://pcmcia.arm.linux.org.uk/
                 2.6 Serial core