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

[Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx>]

Hi,


> -----Original Message-----
> From: Boris Brezillon [mailto:boris.brezillon@xxxxxxxxxxx]
> Sent: Monday, October 22, 2018 2:46 PM
> To: Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx>
> Cc: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>; richard@xxxxxx; Mark
> Brown <broonie@xxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx;
> nicolas.ferre@xxxxxxxxxxxxx; marek.vasut@xxxxxxxxx;
> cyrille.pitchen@xxxxxxxxxxxxx; linux-mtd@xxxxxxxxxxxxxxxxxxx;
> Cristian.Birsan@xxxxxxxxxxxxx; Cyrille Pitchen <cyrille.pitchen@xxxxxxxxxx>;
> computersforpeace@xxxxxxxxx; dwmw2@xxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH v3 1/2] mtd: spi-nor: add support to non-uniform SFDP SPI
> NOR flash memories
> 
> On Mon, 22 Oct 2018 06:04:13 +0000
> Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx> wrote:
> 
> 
With below patch, it gets stuck in for loop of "+       for (nmaps = 0; i< smpt_len; nmaps++) {".

[    1.624684] m25p80 spi0.0: found s25fl512s, expected m25p80
[    1.630377] Start [addr_width:00000000, read_dumy:08, read_opcode:00000000]
[    1.637335] spi_nor_get_map_in_use:2882 smpt[0]=08ff65fc
[    1.642641] spi_nor_get_map_in_use:2882 smpt[1]=00000004
[    1.647945] spi_nor_get_map_in_use:2882 smpt[2]=04ff65fc
[    1.653248] spi_nor_get_map_in_use:2882 smpt[3]=00000002
[    1.658551] spi_nor_get_map_in_use:2882 smpt[4]=02ff65fd
[    1.663855] spi_nor_get_map_in_use:2882 smpt[5]=00000004
[    1.669158] spi_nor_get_map_in_use:2882 smpt[6]=ff0201fe
[    1.674461] spi_nor_get_map_in_use:2882 smpt[7]=00007ff1
[    1.679766] spi_nor_get_map_in_use:2882 smpt[8]=00037ff4
[    1.685070] spi_nor_get_map_in_use:2882 smpt[9]=03fbfff4
[    1.690375] spi_nor_get_map_in_use:2882 smpt[10]=ff0203fe
[    1.695768] spi_nor_get_map_in_use:2882 smpt[11]=03fbfff4
[    1.701158] spi_nor_get_map_in_use:2882 smpt[12]=00037ff4
[    1.706550] spi_nor_get_map_in_use:2882 smpt[13]=00007ff1
[    1.711940] spi_nor_get_map_in_use:2882 smpt[14]=ff0005ff
[    1.717330] spi_nor_get_map_in_use:2882 smpt[15]=03fffff4
[    1.722720] smpt[0]=[addr_width:00000000, read_dumy:08, read_opcode:00000065]
[    1.729861] spi_nor_get_map_in_use:2912 map_id=1


--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -2863,26 +2863,36 @@ static u8 spi_nor_smpt_read_dummy(const struct spi_nor *nor, const u32 settings)
  * @nor:       pointer to a 'struct spi_nor'
  * @smpt:      pointer to the sector map parameter table
  */
-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;

+       pr_info("Start [addr_width:%08x, read_dumy:%0x8, read_opcode:%08x]\n", nor->addr_width, nor->read_dummy, 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]);
                nor->read_opcode = SMPT_CMD_OPCODE(smpt[i]);
+               pr_info("smpt[%d]=[addr_width:%08x, read_dumy:%0x8, read_opcode:%08x]\n", i, nor->addr_width, nor->read_dummy, nor->read_opcode);
+
                addr = smpt[i + 1];

                err = spi_nor_read_raw(nor, addr, 1, &data_byte);
@@ -2894,18 +2904,36 @@ 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;
        }

-       /* Find the matching configuration map */
-       while (SMPT_MAP_ID(smpt[i]) != map_id) {
-               if (smpt[i] & SMPT_DESC_END)
-                       goto out;
+       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__);
+
+       for (nmaps = 0; i< smpt_len; nmaps++) {
+               if((smpt[i] & SMPT_DESC_TYPE_MAP))
+                       continue;
+
+               if(!map_id_is_valid) {
+                       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;
+       pr_info("End [addr_width:%08x, read_dumy:%0x8, read_opcode:%08x]\n", nor->addr_width, nor->read_dummy, nor->read_opcode);
        /* fall through */
 out:
        nor->addr_width = addr_width;

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