5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sean Nyekjaer <sean@xxxxxxxxxx>
commit 8cba323437a49a45756d661f500b324fc2d486fe upstream.
Prevent rawnand access while in a suspended state.
Commit 013e6292aaf5 ("mtd: rawnand: Simplify the locking") allows the
rawnand layer to return errors rather than waiting in a blocking wait.
Tested on a iMX6ULL.
Fixes: 013e6292aaf5 ("mtd: rawnand: Simplify the locking")
Signed-off-by: Sean Nyekjaer <sean@xxxxxxxxxx>
Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Link: https://lore.kernel.org/linux-mtd/20220208085213.1838273-1-sean@xxxxxxxxxx
[florian: Adjust rawnand.h members documentation and position]
Signed-off-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mtd/nand/raw/nand_base.c | 44 +++++++++++++++++----------------------
include/linux/mtd/rawnand.h | 2 +
2 files changed, 22 insertions(+), 24 deletions(-)
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -359,16 +359,19 @@ static int nand_isbad_bbm(struct nand_ch
*
* Return: -EBUSY if the chip has been suspended, 0 otherwise
*/
-static int nand_get_device(struct nand_chip *chip)
+static void nand_get_device(struct nand_chip *chip)
{
- mutex_lock(&chip->lock);
- if (chip->suspended) {
+ /* Wait until the device is resumed. */
+ while (1) {
+ mutex_lock(&chip->lock);
+ if (!chip->suspended) {
+ mutex_lock(&chip->controller->lock);
+ return;
+ }
mutex_unlock(&chip->lock);
- return -EBUSY;
- }
- mutex_lock(&chip->controller->lock);
- return 0;
+ wait_event(chip->resume_wq, !chip->suspended);
+ }
}
/**
@@ -593,9 +596,7 @@ static int nand_block_markbad_lowlevel(s
nand_erase_nand(chip, &einfo, 0);
/* Write bad block marker to OOB */
- ret = nand_get_device(chip);
- if (ret)
- return ret;
+ nand_get_device(chip);
ret = nand_markbad_bbm(chip, ofs);
nand_release_device(chip);
@@ -3576,9 +3577,7 @@ static int nand_read_oob(struct mtd_info
ops->mode != MTD_OPS_RAW)
return -ENOTSUPP;
- ret = nand_get_device(chip);
- if (ret)
- return ret;
+ nand_get_device(chip);
if (!ops->datbuf)
ret = nand_do_read_oob(chip, from, ops);
@@ -4122,13 +4121,11 @@ static int nand_write_oob(struct mtd_inf
struct mtd_oob_ops *ops)
{
struct nand_chip *chip = mtd_to_nand(mtd);
- int ret;
+ int ret = 0;
ops->retlen = 0;
- ret = nand_get_device(chip);
- if (ret)
- return ret;
+ nand_get_device(chip);
switch (ops->mode) {
case MTD_OPS_PLACE_OOB:
@@ -4184,9 +4181,7 @@ int nand_erase_nand(struct nand_chip *ch
return -EINVAL;
/* Grab the lock and see if the device is available */
- ret = nand_get_device(chip);
- if (ret)
- return ret;
+ nand_get_device(chip);
/* Shift to get first page */
page = (int)(instr->addr >> chip->page_shift);
@@ -4273,7 +4268,7 @@ static void nand_sync(struct mtd_info *m
pr_debug("%s: called\n", __func__);
/* Grab the lock and see if the device is available */
- WARN_ON(nand_get_device(chip));
+ nand_get_device(chip);
/* Release it and go back */
nand_release_device(chip);
}
@@ -4290,9 +4285,7 @@ static int nand_block_isbad(struct mtd_i
int ret;
/* Select the NAND device */
- ret = nand_get_device(chip);
- if (ret)
- return ret;
+ nand_get_device(chip);
nand_select_target(chip, chipnr);
@@ -4354,6 +4347,8 @@ static void nand_resume(struct mtd_info
pr_err("%s called for a chip which is not in suspended state\n",
__func__);
mutex_unlock(&chip->lock);
+
+ wake_up_all(&chip->resume_wq);
}
/**
@@ -5014,6 +5009,7 @@ static int nand_scan_ident(struct nand_c
chip->cur_cs = -1;
mutex_init(&chip->lock);
+ init_waitqueue_head(&chip->resume_wq);
/* Enforce the right timings for reset/detection */
onfi_fill_data_interface(chip, NAND_SDR_IFACE, 0);
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -1064,6 +1064,7 @@ struct nand_legacy {
* @lock: lock protecting the suspended field. Also used to
* serialize accesses to the NAND device.
* @suspended: set to 1 when the device is suspended, 0 when it's not.
+ * @resume_wq: wait queue to sleep if rawnand is in suspended state.
* @bbt: [INTERN] bad block table pointer
* @bbt_td: [REPLACEABLE] bad block table descriptor for flash
* lookup.
@@ -1117,6 +1118,7 @@ struct nand_chip {
struct mutex lock;
unsigned int suspended : 1;
+ wait_queue_head_t resume_wq;
uint8_t *oob_poi;
struct nand_controller *controller;
