[U-Boot-Users] PATCH: support JEDEC flash roms in CFI-flash framework

[Michael Schwingen]

On Tue, Nov 13, 2007 at 03:45:40PM +0100, Stefan Roese wrote:
> 
> A reference to a mail thread is not good in a commit description. Please try 
> to add all necessary infos directly in this text.

OK. I will await further comments and then re-submit with documentation.

> > +	debug("Found JEDEC Flash: %s\n", jedec_entry->name);
> > +	info->vendor = jedec_entry->CmdSet;
> > +	/* Todo: do we need device-specific timeouts? */
> > +	info->erase_blk_tout = 30000;
> > +	info->buffer_write_tout = 1000;
> > +	info->write_tout = 100;
> > +	info->name = jedec_entry->name;
> 
> How does the Linux driver handle this timeout? Is it device specific there?

No. I do not completely understand all the Linux MTD/Flash code, but a quick
glance did not show any timer-based timeout handling - it seems the code
relies on the timeout bit from the flash (I looked at 2.6.21.6).

The Jedec code has no device-specific timeout values in the tables, so I
used hardcoded values which seem "big enough". To make this perfect, we
would really need device-specific values, but from my expecience, relying on
the flash status register to signal timeouts is sufficient.

cu
Michael