linux-kernel - [PATCH v2] mtd: spi-nor: Fix address width on flash chips

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Message-Id: <20201004213204.11584-1-bert@biot.com>
Date:   Sun,  4 Oct 2020 23:32:04 +0200
From:   Bert Vermeulen <bert@...t.com>
To:     tudor.ambarus@...rochip.com, miquel.raynal@...tlin.com,
        richard@....at, vigneshr@...com, linux-mtd@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Cc:     Bert Vermeulen <bert@...t.com>
Subject: [PATCH v2] mtd: spi-nor: Fix address width on flash chips > 16MB

If a flash chip has more than 16MB capacity but its BFPT reports
BFPT_DWORD1_ADDRESS_BYTES_3_OR_4, the spi-nor framework defaults to 3.

The check in spi_nor_set_addr_width() doesn't catch it because addr_width
did get set. This fixes that check.

Signed-off-by: Bert Vermeulen <bert@...t.com>
---
 drivers/mtd/spi-nor/core.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 0369d98b2d12..a2c35ad9645c 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -3009,13 +3009,15 @@ static int spi_nor_set_addr_width(struct spi_nor *nor)
 		/* already configured from SFDP */
 	} else if (nor->info->addr_width) {
 		nor->addr_width = nor->info->addr_width;
-	} else if (nor->mtd.size > 0x1000000) {
-		/* enable 4-byte addressing if the device exceeds 16MiB */
-		nor->addr_width = 4;
 	} else {
 		nor->addr_width = 3;
 	}
 
+	if (nor->addr_width == 3 && nor->mtd.size > 0x1000000) {
+		/* enable 4-byte addressing if the device exceeds 16MiB */
+		nor->addr_width = 4;
+	}
+
 	if (nor->addr_width > SPI_NOR_MAX_ADDR_WIDTH) {
 		dev_dbg(nor->dev, "address width is too large: %u\n",
 			nor->addr_width);
-- 
2.17.1