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

[Yogesh Narayan Gaur]

Hi Boris,

> -----Original Message-----
> From: Boris Brezillon [mailto:boris.brezillon@xxxxxxxxxxx]
> Sent: Wednesday, October 17, 2018 1:00 PM
> To: Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx>
> Cc: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxxx>; Tudor Ambarus
> <tudor.ambarus@xxxxxxxxxxxxx>; marek.vasut@xxxxxxxxx;
> dwmw2@xxxxxxxxxxxxx; computersforpeace@xxxxxxxxx; richard@xxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; nicolas.ferre@xxxxxxxxxxxxx;
> cyrille.pitchen@xxxxxxxxxxxxx; linux-mtd@xxxxxxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; Cristian.Birsan@xxxxxxxxxxxxx
> Subject: Re: [PATCH v3 1/2] mtd: spi-nor: add support to non-uniform SFDP SPI
> NOR flash memories
> 
> 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.
Yes, that's only I have stated in my first mail that instead of 1-4-4 mode read opcode is being sent for 1-1-4 mode.
> >
> 
> Can you try with this patch applied?
> 
With suggested patch, read for protocol 1-4-4 working correctly.

	[    1.625360] m25p80 spi0.0: found s25fl512s, expected m25p80                                                                   
	[    1.631094] m25p80 spi0.0: failed to parse SMPT (err = -22)                                                                   
	[    1.636661] 261 8c4c780 opcode(read:eb, pp:2, erase:d8)                                                                       
	[    1.641878] 266 8c4c780 opcode(read:ec, pp:12, erase:dc)                                                                      
	[    1.647200] m25p80 spi0.0: s25fl512s (65536 Kbytes)         

Without this patch, param_headers are getting freed and restoring previous erase map i.e. opcode related to 1-1-4 protocol.

--
Regards
Yogesh Gaur

> --->8---
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index
> 9407ca5f9443..cf33d834698c 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -3132,6 +3132,17 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor,
>                 switch (SFDP_PARAM_HEADER_ID(param_header)) {
>                 case SFDP_SECTOR_MAP_ID:
>                         err = spi_nor_parse_smpt(nor, param_header);
> +                       if (err) {
> +                               dev_warn(dev,
> +                                        "failed to parse SMPT (err = %d)\n",
> +                                        err);
> +                               /*
> +                                * SMPT parsing is optional, let's not drop
> +                                * all information we extracted so far just
> +                                * because it failed.
> +                                */
> +                               err = 0;
> +                       }
>                         break;
> 
>                 default: