[PATCH v4] mtd: spi-nor: fix nor->addr_width when its value configured from SFDP does not match the actual width

From: Liu Xiang <liu.xiang6@zte.com.cn>
To: linux-mtd@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, tudor.ambarus@microchip.com,
	marek.vasut@gmail.com, dwmw2@infradead.org,
	computersforpeace@gmail.com, miquel.raynal@bootlin.com,
	richard@nod.at, vigneshr@ti.com, liuxiang_1999@126.com,
	Liu Xiang <liu.xiang6@zte.com.cn>
Subject: [PATCH v4] mtd: spi-nor: fix nor->addr_width when its value configured from SFDP does not match the actual width
Date: Tue, 25 Jun 2019 00:00:46 +0800	[thread overview]
Message-ID: <1561392046-10487-1-git-send-email-liu.xiang6@zte.com.cn> (raw)

IS25LP256 gets BFPT_DWORD1_ADDRESS_BYTES_3_ONLY from BFPT table for
address width. But in actual fact the flash can support 4-byte address.
Use a post bfpt fixup hook to overwrite the address width advertised by
the BFPT.

Suggested-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Liu Xiang <liu.xiang6@zte.com.cn>

---

Changes in v4:
 update the comment suggested by Tudor.
---
 drivers/mtd/spi-nor/spi-nor.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 73172d7..ce153c4 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1687,6 +1687,28 @@ static int sr2_bit7_quad_enable(struct spi_nor *nor)
 		.flags = SPI_NOR_NO_FR | SPI_S3AN,
 
 static int
+is25lp256_post_bfpt_fixups(struct spi_nor *nor,
+			   const struct sfdp_parameter_header *bfpt_header,
+			   const struct sfdp_bfpt *bfpt,
+			   struct spi_nor_flash_parameter *params)
+{
+	/*
+	 * IS25LP256 supports 4B opcodes, but the BFPT advertises a
+	 * BFPT_DWORD1_ADDRESS_BYTES_3_ONLY address width.
+	 * Overwrite the address width advertised by the BFPT.
+	 */
+	if ((bfpt->dwords[BFPT_DWORD(1)] & BFPT_DWORD1_ADDRESS_BYTES_MASK) ==
+		BFPT_DWORD1_ADDRESS_BYTES_3_ONLY)
+		nor->addr_width = 4;
+
+	return 0;
+}
+
+static struct spi_nor_fixups is25lp256_fixups = {
+	.post_bfpt = is25lp256_post_bfpt_fixups,
+};
+
+static int
 mx25l25635_post_bfpt_fixups(struct spi_nor *nor,
 			    const struct sfdp_parameter_header *bfpt_header,
 			    const struct sfdp_bfpt *bfpt,
@@ -1827,7 +1849,8 @@ static int sr2_bit7_quad_enable(struct spi_nor *nor)
 			SECT_4K | SPI_NOR_DUAL_READ) },
 	{ "is25lp256",  INFO(0x9d6019, 0, 64 * 1024, 512,
 			SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
-			SPI_NOR_4B_OPCODES) },
+			SPI_NOR_4B_OPCODES)
+			.fixups = &is25lp256_fixups },
 	{ "is25wp032",  INFO(0x9d7016, 0, 64 * 1024,  64,
 			SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
 	{ "is25wp064",  INFO(0x9d7017, 0, 64 * 1024, 128,
-- 
1.9.1

