[PATCH v5 03/28] mtd: spi-nor: Make sure the QE bit is kept enabled if useful

[Miquel Raynal]

Not all chips implement the 4BAIT table which typically indicates the
program capability, while many of them do implement the relevant SFDP
parts indicating the read capabilities. In such a situation, programs
can happen in single mode (1-1-1) and reads in quad mode (1-1-4 or
1-4-4). For the reads to work in such condition, the QE bit must be set.
In case we later use the spi_nor_write_16bit_sr_and_check() helper with
a chip with such configuration, the QE bit would get incorrectly
cleared.

Make sure this doesn't happen by keeping the QE bit under a simpler
condition:
- the quad enable hook is there (no change)
- and at least one of the two protocols is based on quad I/O cycles

Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>
---
 drivers/mtd/spi-nor/core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 5dd0b3cb5250..394c27de02d6 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -869,8 +869,8 @@ static int spi_nor_write_16bit_sr_and_check(struct spi_nor *nor, u8 sr1)
 		ret = spi_nor_read_cr(nor, &sr_cr[1]);
 		if (ret)
 			return ret;
-	} else if (spi_nor_get_protocol_width(nor->read_proto) == 4 &&
-		   spi_nor_get_protocol_width(nor->write_proto) == 4 &&
+	} else if ((spi_nor_get_protocol_width(nor->read_proto) == 4 ||
+		    spi_nor_get_protocol_width(nor->write_proto) == 4) &&
 		   nor->params->quad_enable) {
 		/*
 		 * If the Status Register 2 Read command (35h) is not

-- 
2.53.0