From b9ae609fdbb7f8149a13bb9c67006b7237cbf83e Mon Sep 17 00:00:00 2001
From: Brian Norris <computersforpeace@gmail.com>
Date: Tue, 6 May 2014 00:46:16 +0530
Subject: [PATCH] mtd: nand: don't use read_buf for 8-bit ONFI transfers
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Porting below commit from linux-tree, preserving original authorship & commit log
commit bd9c6e99b58255b9de1982711ac9487c9a2f18be
Author: Brian Norris <computersforpeace@gmail.com>
mtd: nand: don't use read_buf for 8-bit ONFI transfers
Use a repeated read_byte() instead of read_buf(), since for x16 buswidth
devices, we need to avoid the upper I/O[16:9] bits. See the following
commit for reference:
commit 05f7835975dad6b3b517f9e23415985e648fb875 (from linux-tree)
Author: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Date: Thu Dec 5 22:22:04 2013 +0100
mtd: nand: don't use {read,write}_buf for 8-bit transfers
Now, I think that all barriers to probing ONFI on x16 devices are
removed, so remove the check from nand_flash_detect_onfi().
Signed-off-by: Pekon Gupta <pekon@ti.com>
---
drivers/mtd/nand/nand_base.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 1ce55fde8b..5d3232c634 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2582,7 +2582,7 @@ static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
int *busw)
{
struct nand_onfi_params *p = &chip->onfi_params;
- int i;
+ int i, j;
int val;
/* Try ONFI for unknown chip or LP */
@@ -2593,7 +2593,8 @@ static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
for (i = 0; i < 3; i++) {
- chip->read_buf(mtd, (uint8_t *)p, sizeof(*p));
+ for (j = 0; j < sizeof(*p); j++)
+ ((uint8_t *)p)[j] = chip->read_byte(mtd);
if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
le16_to_cpu(p->crc)) {
pr_info("ONFI param page %d valid\n", i);
--
2.39.5