Hi Francesco,
francesco@dolcini.it wrote on Mon, 5 Dec 2022 12:26:44 +0100:
On Fri, Dec 02, 2022 at 06:08:22PM +0100, Marek Vasut wrote:
But here I would say this is a firmware bug and it might have to be handled like a firmware bug, i.e. with fixup in the partition parser. I seem to be changing my opinion here again.
I was thinking at this over the weekend, and I came to the following ideas:
- we need some improvement on the fixup we already have in the partition parser. We cannot ignore the fdt produced by U-Boot - as bad as it is.
- the proposed fixup is fine for the immediate need, but it is not going to be enough to cover the general issue with the U-Boot generated partitions. U-Boot might keep generating partitions as direct child of the nand controller even when a partitions{} node is available. In this case the current parser just fails since it looks only into it and it will find it empty.
- the current U-Boot only handle partitions{} as a direct child of the nand-controller, the nand-chip is ignored. This is not the way it is supposed to work. U-Boot code would need to be improved.
I've been thinking about it this weekend as well and the current fix which "just set" s_cell to 1 seems risky for me, it is typically the type of quick & dirty fix that might even break other board (nobody knew that U-Boot current logic expected #size-cells to be set in the DT, what if another "broken" DT expects the opposite...), not mentioning potential issues with big storages (> 4GiB).
All in all, I really think we should revert the DT change now, reverting as little to no drawbacks besides a dt_binding_check warning and gives us time to deal with it properly (both in U-Boot and Linux).
With all of that said I think that Miquel is right
When a patch breaks a board and there is no straight fix, you revert it, then you think harder. That's what I am saying. This is a temporary solution.
?
Francesco
Thanks, Miquèl