From c21b0ca525bd818428a62dd267697071822cc9a9 Mon Sep 17 00:00:00 2001
From: Michael Trimarchi <michael@amarulasolutions.com>
Date: Fri, 21 Oct 2022 08:05:36 +0200
Subject: [PATCH] mtd: nand: make Samsung SLC NAND usable again
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit
Upstream linux commit 69fc01296c9281
commit a1286a1fc416 ("mtd: nand: Move Samsung specific init/detection
logic in nand_samsung.c") introduced a regression for Samsung SLC NAND
chips. Prior to this commit chip->bits_per_cell was initialized by calling
nand_get_bits_per_cell() before using nand_is_slc().
With the offending commit this call is skipped, leaving
chip->bits_per_cell cleared to zero when the manufacturer specific
'.detect' function calls nand_is_slc() which in turn interprets
bits_per_cell != 1 as indication for an MLC chip.
The effect is that e.g. a K9F1G08U0F NAND chip is falsely detected as
MLC NAND with 4KiB page size rather than SLC with 2KiB page size.
Add a call to nand_get_bits_per_cell() before calling the .detect hook
function in nand_manufacturer_detect(), so that the nand_is_slc()
calls in the manufacturer specific code will return correct results.
Reported-by: Marcin GoÅaÅ <marcingol30@gmail.com>
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Reviewed-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Link: https://lore.kernel.org/all/20221021060536.11747-1-michael@amarulasolutions.com
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---
drivers/mtd/nand/raw/nand_base.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 215b9ba84f..bc61ad03eb 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -4171,10 +4171,13 @@ static void nand_manufacturer_detect(struct nand_chip *chip)
* nand_decode_ext_id() otherwise.
*/
if (chip->manufacturer.desc && chip->manufacturer.desc->ops &&
- chip->manufacturer.desc->ops->detect)
+ chip->manufacturer.desc->ops->detect) {
+ /* The 3rd id byte holds MLC / multichip data */
+ chip->bits_per_cell = nand_get_bits_per_cell(chip->id.data[2]);
chip->manufacturer.desc->ops->detect(chip);
- else
+ } else {
nand_decode_ext_id(chip);
+ }
}
/*
--
2.39.5