[U-Boot] [U-Boot, v1, 1/4] mtd: nand: add NAND_BUSWIDTH_AUTO to autodetect bus width

[Scott Wood]

On Thu, 2013-11-14 at 04:32 +0000, Gupta, Pekon wrote:
> > From: Scott Wood [mailto:scottwood at freescale.com]
> > On Tue, Sep 10, 2013 at 06:57:05PM +0530, pekon gupta wrote:
> > > From: Matthieu CASTET <matthieu.castet at parrot.com>
> > >
> > > This patch is slightly modified from following linux patch
> > > http://lists.infradead.org/pipermail/linux-mtd/2012-
> > November/044803.html
> >
> > Which is now commit 64b37b2a63eb2f80b65c7185f0013f8ffc637ae3
> >
> > > So retaining the authorship to Matthieu CASTET
> > <matthieu.castet at parrot.com>
> > > *Modifications from original patch*
> > > reset chip->read_byte, chip->read_buf, chip->write_buf before setting
> > defaults.
> >
> > Why does U-Boot need this if Linux doesn't?
> >
> Yes, I plan to drop this patch.
> Reason: Though this feature was introduced in linux long back, but hardly
> any mtd/nand drivers using this. Also there are alternative approaches
> which do not require any change in individual controller drivers, but just
> in generic NAND driver.
> I have proposed them in linux mtd-maillist, I'll propose same in my next
> version of patch-set.
> 
> http://lists.infradead.org/pipermail/linux-mtd/2013-November/049744.html

Hmm, I don't like the "kill NAND_BUSWIDTH_AUTO" sentiment.  The device
tree is for describing things that can't be reasonably discovered
through hardware interfaces.  ONFI identification always being x8 seems
designed specifically to allow said discovery.

-Scott