Re: [PATCH 1/2] mtd: spinand: winbond: add support for W25N04LW

On Mon, Aug 10, 2026 at 02:43:52PM +0200, Miquel Raynal wrote:
> Hi Dominique,
> 
> On 10/08/2026 at 17:28:32 +09, Dominique MARTINET <[email protected]> wrote:
> 
> > Md Sadre Alam wrote on Fri, Aug 07, 2026 at 12:13:38PM +0530:
> >> Add support for Winbond W25N04LW 4Gbit SPI-NAND.
> >> It has 8-bit on-die ECC and a 4096+256 byte page
> >> (4096 byte main area, 128 byte usable OOB once
> >> on-chip ECC hides the 128 byte parity area),
> >> organized as 2048 blocks of 64 pages each, unlike
> >> the existing 2048 byte page W25N04KV/W25N04KW parts.
> >
> > This is pretty good timing, I was just looking at sending a patch for
> > W25N04LW myself!
> >
> > I agree with Miquèl that your patch looks odd, you wrote
> >> +		     NAND_MEMORG(1, 4096, 128, 64, 2048, 40, 1, 1, 1),
> > but the erase blocks are 256K long so it should be
> > +		     NAND_MEMORG(1, 4096, 256, 64, 2048, 40, 1, 1, 1),
> >
> > did you actually test this device?
> >
> > If it helps, the datasheet for W25N04LWZExx / W25N04LWTBxx is freely
> > available from digikey here[1]
> > [1] https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/7182/W25N04LWZExx_W25N04LWTBxx_RevD_2025-08-05.pdf
> 
> Thanks for all the feedback, Sadre, can you please propose an udpate
> with these details and changes?
I do not currently have access to this device, so I cannot properly
validate an updated version on hardware.

Given that the current patch needs the OOB size fixed to 256, and likely
the OOB layout adjusted accordingly, I think it is better if Dominique sends
his tested version. I am fine with him taking over this patch.

> 
> > (And it also supports continuous read, so I'm curious to see if it'd
> > work with the recent continous read support from Miquèl[2] merged in
> > 7.2... I'm not familiar with the subsystem so will need a bit of time to
> > plug all the hooks in properly)
> > [2]
> > https://lore.kernel.org/linux-mtd/20260429-winbond-v6-18-rc1-cont-read-v3-0-0f38b3c229ad@bootlin.com/
> 
> If it has continuous read, it requires the flag and a hook to
> enable/disable the feature. The existing Winbond helper may already be
> enough for it. You can test it with a recent version of mtd-utils, I
> added options to nanddump, nandbiterrs and flash_speed for that.
> 
> If Sadre dooesn't do it, you can propose a follow-up patch.

I currently do not have access to this device to test continuous read,
so please go ahead with the follow-up patch if you have hardware to
validate it.

Thanks,
Alam.

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