mtd: spi-nor: Clear WEL bit when erase or program errors occur

When an Erase or Program error occurs on a spansion/cypress or a
micron flash, the WEL bit remains set to one and should be cleared
with a WRDI command in order to protect against inadvertent writes
that can possible corrupt the contents of the memory.

Winbond, macronix, gd, etc., do not support the E_ERR and P_ERR bits in the
Status Register and always clear the WEL bit regardless of the outcome
of the erase or page program operation (ex w25q40bw, MX25L25635E).

Issue a WRDI command when erase or page program errors occur.

Reported-by: John Garry <[email protected]>
Signed-off-by: Tudor Ambarus <[email protected]>
Tested-by: John Garry <[email protected]>

Author: ambarus

drivers/mtd/spi-nor/core.c

@@ -559,6 +559,17 @@ static int spi_nor_sr_ready(struct spi_nor *nor)
 			dev_err(nor->dev, "Programming Error occurred\n");
 
 		spi_nor_clear_sr(nor);
+
+		/*
+		 * WEL bit remains set to one when an erase or page program
+		 * error occurs. Issue a Write Disable command to protect
+		 * against inadvertent writes that can possibly corrupt the
+		 * contents of the memory.
+		 */
+		ret = spi_nor_write_disable(nor);
+		if (ret)
+			return ret;
+
 		return -EIO;
 	}
 
@@ -615,6 +626,17 @@ static int spi_nor_fsr_ready(struct spi_nor *nor)
 			"Attempted to modify a protected sector.\n");
 
 		spi_nor_clear_fsr(nor);
+
+		/*
+		 * WEL bit remains set to one when an erase or page program
+		 * error occurs. Issue a Write Disable command to protect
+		 * against inadvertent writes that can possibly corrupt the
+		 * contents of the memory.
+		 */
+		ret = spi_nor_write_disable(nor);
+		if (ret)
+			return ret;
+
 		return -EIO;
 	}