mtd: spi-nor: swp: check SR_TB flag when getting tb_mask

When the chip does not support top/bottom block protect, the tb_mask
must be set to 0, otherwise SR1 bit5 will be unexpectedly modified.

Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
Fixes: 3dd8012a8eeb ("mtd: spi-nor: add TB (Top/Bottom) protect support")
Reviewed-by: Michael Walle <mwalle@kernel.org>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>

diff --git a/drivers/mtd/spi-nor/swp.c b/drivers/mtd/spi-nor/swp.c
index 9b07f83aeac76dce2109f90dfa1534c9bd93330d..e67a81dbb6bf6d12018158aa30749de27a7388aa 100644 (file)
--- a/drivers/mtd/spi-nor/swp.c
+++ b/drivers/mtd/spi-nor/swp.c
@@ -28,8 +28,10 @@ static u8 spi_nor_get_sr_tb_mask(struct spi_nor *nor)
 {
        if (nor->flags & SNOR_F_HAS_SR_TB_BIT6)
                return SR_TB_BIT6;
-       else
+       else if (nor->flags & SNOR_F_HAS_SR_TB)
                return SR_TB_BIT5;
+       else
+               return 0;
 }
 
 static u64 spi_nor_get_min_prot_length_sr(struct spi_nor *nor)