RE: [PATCH 2/2][MTD] Add support for > 2GiB MTD devices

From: Bruce_Leonard
Date: Tue Aug 26 2008 - 22:47:57 EST


Now there's something I hadn't thought of. Thanks, I'll look into doing
it that way.


"Tim Anderson" <tanderson@xxxxxxxxxx> wrote on 08/26/2008 06:40:26 PM:

> Bruce,
>
> Since you don't want to change the ABI you need to extend it. Andrew,
should
> he add an new ioctl that passes a new structure definition? That way the
> original code works and you have to do a new ioctl to get the new size
data.
>
> > -----Original Message-----
> > From: linux-mtd-bounces@xxxxxxxxxxxxxxxxxxx
> > [mailto:linux-mtd-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of
> > Bruce_Leonard@xxxxxxxxxx
> > Sent: Tuesday, August 26, 2008 6:21 PM
> > To: Andrew Morton
> > Cc: linux-mtd-bounces@xxxxxxxxxxxxxxxxxxx;
> > linux-mtd@xxxxxxxxxxxxxxxxxxx; David Woodhouse;
> > linux-kernel@xxxxxxxxxxxxxxx; Bruce Leonard
> > Subject: Re: [PATCH 2/2][MTD] Add support for > 2GiB MTD devices
> >
> > linux-mtd-bounces@xxxxxxxxxxxxxxxxxxx wrote on 08/26/2008 04:55:36 PM:
> >
> > > On Thu, 21 Aug 2008 19:00:55 -0700 (GMT-07:00)
> > > Bruce Leonard <brucle@xxxxxxxxxxxxx> wrote:
> > >
> > > > --- a/include/mtd/mtd-abi.h
> > > > +++ b/include/mtd/mtd-abi.h
> > > > @@ -6,7 +6,7 @@
> > > > #define __MTD_ABI_H__
> > > >
> > > > struct erase_info_user {
> > > > - uint32_t start;
> > > > + uint64_t start;
> > > > uint32_t length;
> > > > };
> > > >
> > > > @@ -50,7 +50,7 @@ struct mtd_oob_buf {
> > > > struct mtd_info_user {
> > > > uint8_t type;
> > > > uint32_t flags;
> > > > - uint32_t size; // Total size of the MTD
> > > > + uint64_t size; // Total size of the MTD
> > > > uint32_t erasesize;
> > > > uint32_t writesize;
> > > > uint32_t oobsize; // Amount of OOB data per block (e.g. 16)
> > >
> > > This changes the kernel<->userspace ABI and is hence a big no-no. I
> > > assume that this change will cause old userspace to
> > malfunction on new
> > > kernels, and vice versa.
> > >
> >
> > Well, in my posting I noted that the mtd-utils were broken
> > because of this
> > but I didn't really have any idea as to how to fix things. I
> > can see why
> > it would be a big no-no to change this. Do you have any
> > suggestions on
> > what I could do differently to prevent making that change?
> >
> > > Supporting >2Gb MTD devices sounds useful (I'm surprised
> > that we don't
> > > already do so).
> > >
> >
> > There was a LOT of interest in this over the last few months
> > while I was
> > working on it, but a very suprising silence has developed
> > since I posted
> > the patches. I guess I'm more cutting edge than I thought :).
> >
> > > Please cc linux-mtd@xxxxxxxxxxxxxxxxxxx (at least) on MTD-related
> > > patches, thanks.
> >
> > I started with the MTD list and then also posted to lkml when
> > I realized I
> > had forgotten to CC it.
> >
> > Thanks.
> >
> > Bruce
> >
> > ______________________________________________________
> > Linux MTD discussion mailing list
> > http://lists.infradead.org/mailman/listinfo/linux-mtd/
> >
>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/