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

DragonBluep · gregkh · commit cca2c083cfcb · 2026-05-23T13:03:18.000+02:00
[ Upstream commit 94645aa ] 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: 3dd8012 ("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> Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/mtd/spi-nor/swp.c b/drivers/mtd/spi-nor/swp.c
@@ -27,8 +27,10 @@ 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)

Original file line number	Diff line number	Diff line change
`@@ -27,8 +27,10 @@ static u8 spi_nor_get_sr_tb_mask(struct spi_nor *nor)`
`27`	`27`	`{`
`28`	`28`	`if (nor->flags & SNOR_F_HAS_SR_TB_BIT6)`
`29`	`29`	`return SR_TB_BIT6;`
`30`		`- else`
	`30`	`+ else if (nor->flags & SNOR_F_HAS_SR_TB)`
`31`	`31`	`return SR_TB_BIT5;`
	`32`	`+ else`
	`33`	`+ return 0;`
`32`	`34`	`}`
`33`	`35`
`34`	`36`	`static u64 spi_nor_get_min_prot_length_sr(struct spi_nor *nor)`