[SkyHigh Memory SPI NAND Driver]

[Mohamed Sardi]

Hello Miquel,

I have a question for bad block marking and checking on Linux... and ECC.

Do you know how bad block marking is done?

1) Bad Block Marking: Are your writing non FF on the first 2 bytes of the OOB? Do you keep Device ECC ON or OFF?
2) Bad block Checking: Do you read the first 2 bytes of the OOB with ECC OFF or do you keep ECC ON?

Thanks,
Mohamed 

On 1/11/24, 3:38 AM, "Miquel Raynal" <miquel.raynal at bootlin.com <mailto:miquel.raynal at bootlin.com>> wrote:


Hi Kim,


> > 2. How many version of this driver we need to develop to support all version of Linux (now being 6.xxx)? 
> 
> We only bring support to the latest mainline kernel, whatever version it could be. So if you send a patch (please follow the contributing guidelines in Documentation/) it should be a diff against the next -rc1 (so it will be v6.8-rc1 in two weeks). You can share diffs for other versions as well on your own website but there is usually no backport of 'new features'.
> 
> [KR] Simply, you can only support for our patch to the latest version. Is that right?


Well, there is only one "mainline", and your contributions must match
the state of this mainline. When applying the patch, the next kernel
and all others following will have support for your chips.
> 
> > For instance if the driver (attached is 5.4), can it be used up to 5.18… or should we modify it starting from version 5.4x. 
> 
> If it compiles, it will probably work as well as the core has not changed much since it's been created, but there is of course no guarantee.
> 
> [KR] Is it possible to apply the patch to old version of Linux community?


On your side you can provide a diff for each kernel version that you
want to support which does not contain your patch series. For all
kernel versions after your changes have been merged, there is nothing
additional to do on your side (besides posting updates/fixes maybe).
You cannot backport a feature to older (stable) kernels.


Thanks,
Miquèl