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

Boris Brezillon
2018-10-17T09:52:37Z

On Wed, 17 Oct 2018 07:46:30 +0000
Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com> wrote:

> 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)
>

Okay, let's try this one to see why the SMPT parsing fails.

--->8---
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 9407ca5f9443..564882c87641 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -2855,23 +2855,31 @@ static u8 spi_nor_smpt_read_dummy(const struct spi_nor *nor, const u32 settings)
* spi_nor_get_map_in_use() - get the configuration map in use
* @nor: pointer to a 'struct spi_nor'
* @smpt: pointer to the sector map parameter table
+ * @smpt_len: number of entries in the smpt array
*/
-static const u32 *spi_nor_get_map_in_use(struct spi_nor *nor, const u32 *smpt)
+static const u32 *spi_nor_get_map_in_use(struct spi_nor *nor, const u32 *smpt,
+ u32 smpt_len)
{
const u32 *ret = NULL;
- u32 i, addr;
+ u32 i, addr, nmaps;
int err;
u8 addr_width, read_opcode, read_dummy;
u8 read_data_mask, data_byte, map_id;
+ bool map_id_is_valid = false;

addr_width = nor->addr_width;
read_dummy = nor->read_dummy;
read_opcode = nor->read_opcode;

+ for (i = 0; i < smpt_len; i++)
+ pr_info("%s:%i smpt[%d] = %08x\n", __func__, __LINE__, i, smpt[i]);
+
map_id = 0;
- i = 0;
/* Determine if there are any optional Detection Command Descriptors */
- while (!(smpt[i] & SMPT_DESC_TYPE_MAP)) {
+ for (i = 0; i < smpt_len; i++) {
+ if (!(smpt[i] & SMPT_DESC_TYPE_MAP))
+ break;
+
read_data_mask = SMPT_CMD_READ_DATA(smpt[i]);
nor->addr_width = spi_nor_smpt_addr_width(nor, smpt[i]);
nor->read_dummy = spi_nor_smpt_read_dummy(nor, smpt[i]);
@@ -2887,18 +2895,40 @@ static const u32 *spi_nor_get_map_in_use(struct spi_nor *nor, const u32 *smpt)
* Configuration that is currently in use.
*/
map_id = map_id << 1 | !!(data_byte & read_data_mask);
+ map_id_is_valid = true;
i = i + 2;
}

+ if (map_id_is_valid)
+ pr_info("%s:%i map_id = %d\n", __func__, __LINE__, map_id);
+ else
+ pr_info("%s:%i no map_id\n", __func__, __LINE__);
+
/* Find the matching configuration map */
- while (SMPT_MAP_ID(smpt[i]) != map_id) {
- if (smpt[i] & SMPT_DESC_END)
- goto out;
+ for (nmaps = 0; i < smpt_len; nmaps++) {
+ if (!(smpt[i] & SMPT_DESC_TYPE_MAP))
+ continue;
+
+ if (!map_id_is_valid) {
+ /*
+ * Command descriptors are optional but if we didn't
+ * find any, we should ensure we have only one map.
+ */
+ if (nmaps) {
+ ret = NULL;
+ break;
+ }
+
+ ret = smpt + i;
+ } else if (map_id == SMPT_MAP_ID(smpt[i])) {
+ ret = smpt + i;
+ break;
+ }
+
/* increment the table index to the next map */
i += SMPT_MAP_REGION_COUNT(smpt[i]) + 1;
}

- ret = smpt + i;
/* fall through */
out:
nor->addr_width = addr_width;
@@ -3020,7 +3050,7 @@ static int spi_nor_parse_smpt(struct spi_nor *nor,
for (i = 0; i < smpt_header->length; i++)
smpt[i] = le32_to_cpu(smpt[i]);

- sector_map = spi_nor_get_map_in_use(nor, smpt);
+ sector_map = spi_nor_get_map_in_use(nor, smpt, smpt_header->length);
if (!sector_map) {
ret = -EINVAL;
goto out;
@@ -3132,6 +3162,17 @@ 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;