Patch "mtd: nand: hynix: add support for 20nm NAND chips" has been added to the 4.12-stable tree

This is a note to let you know that I've just added the patch titled

mtd: nand: hynix: add support for 20nm NAND chips

to the 4.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mtd-nand-hynix-add-support-for-20nm-nand-chips.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Martin Blumenstingl <[email protected]>
Date: Sat, 5 Aug 2017 14:16:24 +0200
Subject: mtd: nand: hynix: add support for 20nm NAND chips

From: Martin Blumenstingl <[email protected]>

commit fd213b5bae800dc00a2930dcd07f63ab9bbff3f9 upstream.

According to the datasheet of the H27UCG8T2BTR the NAND Technology field (6th byte of the "Device Identifier Description", bits 0-2) the following values are possible:
- 0x0 = 48nm
- 0x1 = 41nm
- 0x2 = 32nm
- 0x3 = 26nm
- 0x4 = 20nm
- (all others are reserved)

Fix this by extending the mask for this field to allow detecting value 0x4 (20nm) as valid NAND technology.
Without this the detection of the ECC requirements fails, because the code assumes that the device is a 48nm device (0x4 & 0x3 = 0x0) and aborts with "Invalid ECC requirements" because it cannot map the "ECC Level". Extending the mask makes the ECC requirement detection code recognize this chip as <= 26nm and sets up the ECC step size and ECC strength correctly.

---
 drivers/mtd/nand/nand_hynix.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -477,7 +477,7 @@ static void hynix_nand_extract_ecc_requi
 		 * The ECC requirements field meaning depends on the
 		 * NAND technology.
 		 */
-		u8 nand_tech = chip->id.data[5] & 0x3;
+		u8 nand_tech = chip->id.data[5] & 0x7;
 
 		if (nand_tech < 3) {
 			/* > 26nm, reference: H27UBG8T2A datasheet */

@@ -533,7 +533,7 @@ static void hynix_nand_extract_scramblin
 		if (nand_tech > 0)
 			chip->options |= NAND_NEED_SCRAMBLING;
 	} else {
-		nand_tech = chip->id.data[5] & 0x3;
+		nand_tech = chip->id.data[5] & 0x7;
 
 		/* < 32nm */
 		if (nand_tech > 2)

Patches currently in stable-queue which might be from [email protected] are

queue-4.12/mtd-nand-hynix-add-support-for-20nm-nand-chips.patch