Re: [PATCH v3 1/2] mtd: spi-nor: add support to non-uniform SFDP SPI NOR flash memories

[Boris Brezillon]

On Wed, 17 Oct 2018 09:10:45 +0200
Boris Brezillon <boris.brezillon@xxxxxxxxxxx> wrote:

> On Wed, 17 Oct 2018 09:07:24 +0200
> Boris Brezillon <boris.brezillon@xxxxxxxxxxx> wrote:
> 
> > On Wed, 17 Oct 2018 02:07:43 +0000
> > Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx> wrote:
> >   
> > > >       
> > > Actually there is no entry of s25fs512s in current spi-nor.c file.
> > > For my connected flash part, jedec ID read points to s25fl512s. I
> > > have asked my board team to confirm the name of exact connected flash
> > > part. When I check the data sheet of s25fs512s, it also points to the
> > > same Jedec ID information. { "s25fl512s",  INFO(0x010220, 0x4d00, 256
> > > * 1024, 256, ....}
> > > 
> > > But as stated earlier, if I skip reading SFDP or read using 1-1-1
> > > protocol then read are always correct. For 1-4-4 protocol read are
> > > wrong and on further debugging found that Read code of 0x6C is being
> > > send as opcode instead of 0xEC.
> > > 
> > > If I revert this patch, reads are working fine.    
> > 
> > Can you try with the following patch?
> >   
> 
> Hm, nevermind. The problem is actually not related to 4B vs non-4B mode
> but 1-1-4 vs 1-4-4 modes.
> 

Can you add traces in this loop [1] to see which features are flagged
as supported and which ones are not.

[1]https://elixir.bootlin.com/linux/v4.19-rc8/source/drivers/mtd/spi-nor/spi-nor.c#L2259