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

@@ -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;
 
                default: