[PATCH] mtd: spi-nor: Fix chip erase timeout issue

[Ye Li]

Chip erase support was added to spi_nor_erase, but the timeout
for polling SR ready is not updated and still for sector erase.
So the timeout value is not enough for chip erase on some NOR flash.
Follow kernel implementation to set new timeout for chip erase.

Fixes: b91a0822d752 ("mtd: spi-nor: Add CHIP_ERASE optimization")

Signed-off-by: Ye Li <ye.li at nxp.com>
---
 drivers/mtd/spi/spi-nor-core.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index aea611fef523..338e5856337e 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -44,6 +44,12 @@
 
 #define DEFAULT_READY_WAIT_JIFFIES		(40UL * HZ)
 
+/*
+ * For full-chip erase, calibrated to a 2MB flash (M25P16); should be scaled up
+ * for larger flash
+ */
+#define CHIP_ERASE_2MB_READY_WAIT_JIFFIES	(40UL * HZ)
+
 #define ROUND_UP_TO(x, y)	(((x) + (y) - 1) / (y) * (y))
 
 struct sfdp_parameter_header {
@@ -991,6 +997,7 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
 	bool addr_known = false;
 	u32 addr, len, rem;
 	int ret, err;
+	unsigned long timeout = 0;
 
 	dev_dbg(nor->dev, "at 0x%llx, len %lld\n", (long long)instr->addr,
 		(long long)instr->len);
@@ -1026,6 +1033,15 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
 		if (len == mtd->size &&
 		    !(nor->flags & SNOR_F_NO_OP_CHIP_ERASE)) {
 			ret = spi_nor_erase_chip(nor);
+			/*
+			 * Scale the timeout linearly with the size of the flash, with
+			 * a minimum calibrated to an old 2MB flash. We could try to
+			 * pull these from CFI/SFDP, but these values should be good
+			 * enough for now.
+			 */
+			timeout = max(CHIP_ERASE_2MB_READY_WAIT_JIFFIES,
+				      CHIP_ERASE_2MB_READY_WAIT_JIFFIES *
+				      (unsigned long)(mtd->size / SZ_2M));
 		} else {
 			ret = spi_nor_erase_sector(nor, addr);
 		}
@@ -1035,7 +1051,10 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
 		addr += ret;
 		len -= ret;
 
-		ret = spi_nor_wait_till_ready(nor);
+		if (timeout)
+			ret = spi_nor_wait_till_ready_with_timeout(nor, timeout);
+		else
+			ret = spi_nor_wait_till_ready(nor);
 		if (ret)
 			goto erase_err;
 	}
-- 
2.7.4