[ECOS] Re: Check for illegal address range in io/flash

["Øyvind Harboe" <oyvind.harboe@zylin.com>]

On Dec 11, 2007 2:51 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> On Tue, Dec 11, 2007 at 11:09:40AM +0100, ?yvind Harboe wrote:
> > On Dec 11, 2007 11:03 AM, Andrew Lunn <andrew@lunn.ch> wrote:
> > >
> > > > I mainly want the busted check in flash_erase() to be removed.
> > > > ASSERT's are probably fine.
> > >
>
> What is actually wrong with this check?

I have no idea what this check is supposed to do.

If a valid range is passed in, it is a no-operation, otherwise it does
something mysterious
that looks just wrong to me.

I'm afraid all I can conclude is that it should be deleted as plain
wrong/unused. The
fact that it is harmless for valid ranges has allowed it to survive to date,
that's the antrophic principle for you I guess.

Someone else would have to speak up for it.

It would be a shame if plain wrong harmless code that nobody understands
could never be deleted from eCos :-)

> I don't want to remove this until i fully understand what is causing
> your problem and how this code is wrong. Please could you explain what
> you are seeing.

The problem is that I relied on flash_erase() to return an error upon illegal
address range. When I tested with an illegal address range,
flash_erase() did not
return an error. Upon inspecting the code, I saw something that looked
like it is *trying* to check the address, but I have found no explanation
for that code, so I see a couple of alternatives:

- if nobody understands this code, delete it after a week or two to
wait for someone to
speak up and see what happens. Probably nothing.
- keep this code forever as it is harmless(with valid addresses)
nobody will be hurt by it.
- add address check to flash_erase() & program and return error message


-- 
Øyvind Harboe
http://www.zylin.com - eCos ARM & FPGA  developer kit

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