[PATCH] mtd: spi-nor: fix erase_type array to indicate current map conf

[Tudor.Ambarus]

From: Tudor Ambarus <tudor.amba...@microchip.com>

Bug reported for the out-of-tree S25FS128S flash memory.

BFPT table advertises all the erase types supported by all the
possible map configurations. Update the erase_type array to indicate
which erase types are applicable to the current map configuration.

Backward compatibility test done on sst26vf064b.

Fixes: b038e8e3be72 ("mtd: spi-nor: parse SFDP Sector Map Parameter Table")
Reported-by: Alexander Sverdlin <alexander.sverd...@nokia.com>
Signed-off-by: Tudor Ambarus <tudor.amba...@microchip.com>
---
 drivers/mtd/spi-nor/spi-nor.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 93c9bc8931fc..a71adcd6ddfa 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -3000,7 +3000,8 @@ static int spi_nor_init_non_uniform_erase_map(struct 
spi_nor *nor,
        u64 offset;
        u32 region_count;
        int i, j;
-       u8 erase_type, uniform_erase_type;
+       u8 uniform_erase_type, save_uniform_erase_type;
+       u8 erase_type, regions_erase_type;
 
        region_count = SMPT_MAP_REGION_COUNT(*smpt);
        /*
@@ -3014,6 +3015,7 @@ static int spi_nor_init_non_uniform_erase_map(struct 
spi_nor *nor,
        map->regions = region;
 
        uniform_erase_type = 0xff;
+       regions_erase_type = 0;
        offset = 0;
        /* Populate regions. */
        for (i = 0; i < region_count; i++) {
@@ -3030,13 +3032,38 @@ static int spi_nor_init_non_uniform_erase_map(struct 
spi_nor *nor,
                 */
                uniform_erase_type &= erase_type;
 
+               /*
+                * regions_erase_type mask will indicate all the erase types
+                * supported in this configuration map.
+                */
+               regions_erase_type |= erase_type;
+
                offset = (region[i].offset & ~SNOR_ERASE_FLAGS_MASK) +
                         region[i].size;
        }
 
+       save_uniform_erase_type = map->uniform_erase_type;
        map->uniform_erase_type = spi_nor_sort_erase_mask(map,
                                                          uniform_erase_type);
 
+       if (!regions_erase_type) {
+               /*
+                * Roll back to the previous uniform_erase_type mask, SMPT is
+                * broken.
+                */
+               map->uniform_erase_type = save_uniform_erase_type;
+               return -EINVAL;
+       }
+
+       /*
+        * BFPT table advertises all the erase types supported by all the
+        * possible map configurations. Update the erase_type array to indicate
+        * which erase types are applicable to the current map configuration.
+        */
+       for (i = 0; i < SNOR_ERASE_TYPE_MAX; i++)
+               if (!(regions_erase_type & BIT(erase[i].idx)))
+                       spi_nor_set_erase_type(&erase[i], 0, 0xFF);
+
        spi_nor_region_mark_end(&region[i - 1]);
 
        return 0;
-- 
2.9.4