Merge order in Armada 370/XP (mvebu) NAND support

Merge order in Armada 370/XP (mvebu) NAND support

[Ezequiel Garcia]

Hello,

Now that all the pxa3xx-nand code has been merged by proper maintainers
and is available in each subsystem's trees I'd like to ask for suggestions
regarding a potential problem.

Since v3.12, the pxa3xx-nand driver supports the "armada370-nand"
compatible. This was probably a mistake as little to no NAND support
is present in that release.

The support to handle 4K pages devices (for instance, supporting the Mirabox
board) was submitted later, and is currently in MTD tree, waiting to be
pulled in v3.14.

On the other side, the devicetree files (dts and dtsi) needed to enable
such support was taken through the mvebu tree. Currently, a board booted
using mvebu's for-next branch will try to probe the NAND device
(because the compatible was merged in v3.12) and there's a chance it
hits on of NAND core's BUG().

The patchset containing the devicetree changes was prepared under the
assumption that the driver would be merged first, so no risk existed.

I admit this was a crappy assumption on my side to make (and worse:
it's not the first time I assume this).

Jason/Brian: What do you think we can do?
-- 
Ezequiel Garc?a, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com

Merge order in Armada 370/XP (mvebu) NAND support

[Jason Cooper]

On Fri, Dec 06, 2013 at 03:45:45PM -0300, Ezequiel Garcia wrote:
> Jason/Brian: What do you think we can do?

Revert the change adding the compatible string in the first place?

thx,

Jason.

Merge order in Armada 370/XP (mvebu) NAND support

[Ezequiel Garcia]

On Fri, Dec 06, 2013 at 02:25:40PM -0500, Jason Cooper wrote:
> On Fri, Dec 06, 2013 at 03:45:45PM -0300, Ezequiel Garcia wrote:
> > Jason/Brian: What do you think we can do?
> 
> Revert the change adding the compatible string in the first place?
> 

Yes, that probably is the best thing to do.

Brian: what do you think? I can send you a revert of the
"armada370-nand" compatible addition to be pushed for v3.13-rc4?

The compatible can be added on top of l2-mtd.git, after all
the needed support is in the driver.
-- 
Ezequiel Garc?a, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com

Merge order in Armada 370/XP (mvebu) NAND support

[Brian Norris]

On Fri, Dec 06, 2013 at 07:12:18PM -0300, Ezequiel Garcia wrote:
> On Fri, Dec 06, 2013 at 02:25:40PM -0500, Jason Cooper wrote:
> > On Fri, Dec 06, 2013 at 03:45:45PM -0300, Ezequiel Garcia wrote:
> > > Jason/Brian: What do you think we can do?
> > 
> > Revert the change adding the compatible string in the first place?
> 
> Yes, that probably is the best thing to do.
> 
> Brian: what do you think? I can send you a revert of the
> "armada370-nand" compatible addition to be pushed for v3.13-rc4?

Yes, I think dropping the "armada370-nand" compatible string would be a
good solution for 3.13. Are there any use cases where "armada370-nand"
is needed and operational on 3.12? (e.g., is 2KB page support fine?)
Because if there are *no* valid use cases for compatible =
"armada370-nand" yet, then we might want this to go to 3.12.y stable as
well, right?

> The compatible can be added on top of l2-mtd.git, after all
> the needed support is in the driver.

Sure.

I'll take a look at your "revert" patch and see if we can get it
upstream for 3.13.

Thanks,
Brian