This is a note to let you know that I've just added the patch titled
mtd: rawnand: Ensure the nand chip supports cached reads
to the 6.5-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-rawnand-ensure-the-nand-chip-supports-cached-reads.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f6ca3fb6978f94d95ee79f95085fc22e71ca17cc Mon Sep 17 00:00:00 2001
From: Rouven Czerwinski <r.czerwinski@xxxxxxxxxxxxxx>
Date: Fri, 22 Sep 2023 16:17:16 +0200
Subject: mtd: rawnand: Ensure the nand chip supports cached reads
From: Rouven Czerwinski <r.czerwinski@xxxxxxxxxxxxxx>
commit f6ca3fb6978f94d95ee79f95085fc22e71ca17cc upstream.
Both the JEDEC and ONFI specification say that read cache sequential
support is an optional command. This means that we not only need to
check whether the individual controller supports the command, we also
need to check the parameter pages for both ONFI and JEDEC NAND flashes
before enabling sequential cache reads.
This fixes support for NAND flashes which don't support enabling cache
reads, i.e. Samsung K9F4G08U0F or Toshiba TC58NVG0S3HTA00.
Sequential cache reads are now only available for ONFI and JEDEC
devices, if individual vendors implement this, it needs to be enabled
per vendor.
Tested on i.MX6Q with a Samsung NAND flash chip that doesn't support
sequential reads.
Fixes: 003fe4b9545b ("mtd: rawnand: Support for sequential cache reads")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Rouven Czerwinski <r.czerwinski@xxxxxxxxxxxxxx>
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Link: https://lore.kernel.org/linux-mtd/20230922141717.35977-1-r.czerwinski@xxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mtd/nand/raw/nand_base.c | 3 +++
drivers/mtd/nand/raw/nand_jedec.c | 3 +++
drivers/mtd/nand/raw/nand_onfi.c | 3 +++
include/linux/mtd/jedec.h | 3 +++
include/linux/mtd/onfi.h | 1 +
include/linux/mtd/rawnand.h | 2 ++
6 files changed, 15 insertions(+)
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -5109,6 +5109,9 @@ static void rawnand_check_cont_read_supp
{
struct mtd_info *mtd = nand_to_mtd(chip);
+ if (!chip->parameters.supports_read_cache)
+ return;
+
if (chip->read_retries)
return;
--- a/drivers/mtd/nand/raw/nand_jedec.c
+++ b/drivers/mtd/nand/raw/nand_jedec.c
@@ -94,6 +94,9 @@ int nand_jedec_detect(struct nand_chip *
goto free_jedec_param_page;
}
+ if (p->opt_cmd[0] & JEDEC_OPT_CMD_READ_CACHE)
+ chip->parameters.supports_read_cache = true;
+
memorg->pagesize = le32_to_cpu(p->byte_per_page);
mtd->writesize = memorg->pagesize;
--- a/drivers/mtd/nand/raw/nand_onfi.c
+++ b/drivers/mtd/nand/raw/nand_onfi.c
@@ -303,6 +303,9 @@ int nand_onfi_detect(struct nand_chip *c
ONFI_FEATURE_ADDR_TIMING_MODE, 1);
}
+ if (le16_to_cpu(p->opt_cmd) & ONFI_OPT_CMD_READ_CACHE)
+ chip->parameters.supports_read_cache = true;
+
onfi = kzalloc(sizeof(*onfi), GFP_KERNEL);
if (!onfi) {
ret = -ENOMEM;
--- a/include/linux/mtd/jedec.h
+++ b/include/linux/mtd/jedec.h
@@ -21,6 +21,9 @@ struct jedec_ecc_info {
/* JEDEC features */
#define JEDEC_FEATURE_16_BIT_BUS (1 << 0)
+/* JEDEC Optional Commands */
+#define JEDEC_OPT_CMD_READ_CACHE BIT(1)
+
struct nand_jedec_params {
/* rev info and features block */
/* 'J' 'E' 'S' 'D' */
--- a/include/linux/mtd/onfi.h
+++ b/include/linux/mtd/onfi.h
@@ -55,6 +55,7 @@
#define ONFI_SUBFEATURE_PARAM_LEN 4
/* ONFI optional commands SET/GET FEATURES supported? */
+#define ONFI_OPT_CMD_READ_CACHE BIT(1)
#define ONFI_OPT_CMD_SET_GET_FEATURES BIT(2)
struct nand_onfi_params {
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -225,6 +225,7 @@ struct gpio_desc;
* struct nand_parameters - NAND generic parameters from the parameter page
* @model: Model name
* @supports_set_get_features: The NAND chip supports setting/getting features
+ * @supports_read_cache: The NAND chip supports read cache operations
* @set_feature_list: Bitmap of features that can be set
* @get_feature_list: Bitmap of features that can be get
* @onfi: ONFI specific parameters
@@ -233,6 +234,7 @@ struct nand_parameters {
/* Generic parameters */
const char *model;
bool supports_set_get_features;
+ bool supports_read_cache;
DECLARE_BITMAP(set_feature_list, ONFI_FEATURE_NUMBER);
DECLARE_BITMAP(get_feature_list, ONFI_FEATURE_NUMBER);
Patches currently in stable-queue which might be from r.czerwinski@xxxxxxxxxxxxxx are
queue-6.5/mtd-rawnand-ensure-the-nand-chip-supports-cached-reads.patch
