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

Yogesh Narayan Gaur
2018-10-17T07:46:30Z

Hi Boris,

> -----Original Message-----
> From: Boris Brezillon [mailto:boris.brezillon@bootlin.com]
> Sent: Wednesday, October 17, 2018 1:00 PM
> To: Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com>
> Cc: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>; Tudor Ambarus
> <tudor.ambarus@microchip.com>; marek.vasut@gmail.com;
> dwmw2@infradead.org; computersforpeace@gmail.com; richard@nod.at;
> linux-kernel@vger.kernel.org; nicolas.ferre@microchip.com;
> cyrille.pitchen@microchip.com; linux-mtd@lists.infradead.org; linux-arm-
> kernel@lists.infradead.org; Cristian.Birsan@microchip.com
> 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@bootlin.com> wrote:
>
> > On Wed, 17 Oct 2018 09:07:24 +0200
> > Boris Brezillon <boris.brezillon@bootlin.com> wrote:
> >
> > > On Wed, 17 Oct 2018 02:07:43 +0000
> > > Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com> 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;
>