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

From: JÃrn Engel
Date: Wed Aug 27 2008 - 11:25:59 EST


On Wed, 27 August 2008 17:47:43 +0300, Artem Bityutskiy wrote:
>
> The plus of sysfs I see is that I can add more files to expose more
> information in sysfs, while I can not change MEMGETINFO ioctl. E.g., I
> need to expose sub-page size to user-space, and I cannot do this with
> MEMGETINFO.

sysfs makes adding new attributes easier, yes. But once added you
cannot remove the attribute again - ever. Which means that either way
you need to tread carefully and think twice before making a rash
decision.

> > So what was the reason again why mtd needs two userspace interfaces
> > instead of just one?
>
> I would like to make udev creating MTD devices, instead of creating them
> by hands. Adding MTD to LDM would anyway introduce corresponding sysfs
> files, right? This means we would have one more interface anyway.

Could be useful, I don't mind you sending a patch. However, does this
means that MEMGETINFO64 or some other ioctl should not be done? Should
flash_erase open, read and close 8 seperate files instead of doing a
single ioctl? And should our support for large devices wait for the
sysfs support that has been talked about and not done for about two
years already?

Call me a sceptic.

JÃrn

--
The cheapest, fastest and most reliable components of a computer
system are those that aren't there.
-- Gordon Bell, DEC labratories
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