Hello Scott et al.,
Op 06-06-15 om 00:02 schreef Scott Wood:
On Fri, 2015-06-05 at 13:52 +0200, Roy Spliet wrote:
From: yassin yassinjaffer@gmail.com
Signed-off-by: Roy Spliet r.spliet@ultimaker.com
drivers/mtd/nand/Makefile | 2 +- drivers/mtd/nand/nand_timings.c | 252 ++++++++++++++++++++++++++++++++++++++++ include/linux/mtd/nand.h | 3 + 3 files changed, 256 insertions(+), 1 deletion(-) create mode 100644 drivers/mtd/nand/nand_timings.c
This code comes from Linux and yet I see no acknowledgement of that, much less a statement of which version of Linux this was pulled from.
Correct, my apologies as I should have clarified that "work by Boris Brezillon" does not mean "upsteam work". The code comes from Boris' github tree[1] and contains work that was not yet brought upstream, yet is required for NAND on sunxi to work.
It would probably be better to handle this as part of a general sync with the Linux mtd code.
Ideally yes, but. In upstream Linux MTD we have a few issues to address as shown by Boris' patch-set, most importantly: - NAND chip timings (patch 1 to 3) - Randomisation support (patch 6) - Per-partition settings for ECC and randomisation (left out of my RFC, highly desirable but not strictly required for U-boot booting) - OF definition of all the above
U-Boot has the additional challenge - Partitioning is not done the upstream way, but rather in/around cmd_mtdparts
We started discussion on these topics in the #mtd IRC channel (OFTC), and several ideas have come up. The way I see it these issues can currently either be addressed by bolting/duct-taping/tie-wrapping more layers of indirection on top of upstream MTD framework, but really I feel that it might require a bit more of a structural approach that may or may not break existing drivers. The code I posted as RFC is functional. If you wish to steer towards an MTD sync-up, I highly suggest first getting these issues tackled, and then making sure that we extend the U-boot side of MTD with OF support for everything. This trajectory should include deprecating the current implementation of cmd_mtdparts and hook that command up to the "new" upstream way. In other words: now is probably not the right moment.
I'm afraid that as much as I'd like to, I will not have time to address every single one of these issues (not to mention I am hardly the expert in MTD/NAND). I'm happy to think along with designing a sustainable solution, but I will need someone to chime in when it comes to carrying solutions upstream.
Roy
-Scott
[1] https://github.com/bbrezillon/linux-sunxi/commits/sunxi-nand