The nand_get_device() does not select the chip, but nand_release_device()
does de-select the chip. It is really strange.
With the current code, nand_sync() will de-select the chip, even if the chip
has never been selected.
To make the balance of select/de-select chip, it's better to remove the
de-select chip code in nand_release_device() which makes the code more
clear.
Signed-off-by: Huang Shijie <[email protected]>
---
drivers/mtd/nand/nand_base.c | 35 +++++++++++++++++++++++++----------
1 files changed, 25 insertions(+), 10 deletions(-)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 6eef7fb..861a87d 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -130,15 +130,12 @@ static int check_offs_len(struct mtd_info *mtd,
* nand_release_device - [GENERIC] release chip
* @mtd: MTD device structure
*
- * Deselect, release chip lock and wake up anyone waiting on the device.
+ * Release chip lock and wake up anyone waiting on the device.
*/
static void nand_release_device(struct mtd_info *mtd)
{
struct nand_chip *chip = mtd->priv;
- /* De-select the NAND device */
- chip->select_chip(mtd, -1);
-
/* Release the controller and the chip */
spin_lock(&chip->controller->lock);
chip->controller->active = NULL;
@@ -333,8 +330,10 @@ static int nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
i++;
} while (!res && i < 2 && (chip->bbt_options & NAND_BBT_SCAN2NDPAGE));
- if (getchip)
+ if (getchip) {
+ chip->select_chip(mtd, -1);
nand_release_device(mtd);
+ }
return res;
}
@@ -952,6 +951,7 @@ int nand_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
ret = __nand_unlock(mtd, ofs, len, 0);
out:
+ chip->select_chip(mtd, -1);
nand_release_device(mtd);
return ret;
@@ -1016,6 +1016,7 @@ int nand_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
ret = __nand_unlock(mtd, ofs, len, 0x1);
out:
+ chip->select_chip(mtd, -1);
nand_release_device(mtd);
return ret;
@@ -1552,6 +1553,7 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
chip->select_chip(mtd, chipnr);
}
}
+ chip->select_chip(mtd, -1);
ops->retlen = ops->len - (size_t) readlen;
if (oob)
@@ -1806,6 +1808,7 @@ static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
chip->select_chip(mtd, chipnr);
}
}
+ chip->select_chip(mtd, -1);
ops->oobretlen = ops->ooblen - readlen;
@@ -2188,8 +2191,10 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
chip->select_chip(mtd, chipnr);
/* Check, if it is write protected */
- if (nand_check_wp(mtd))
- return -EIO;
+ if (nand_check_wp(mtd)) {
+ ret = -EIO;
+ goto err_out;
+ }
realpage = (int)(to >> chip->page_shift);
page = realpage & chip->pagemask;
@@ -2201,8 +2206,10 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
chip->pagebuf = -1;
/* Don't allow multipage oob writes with offset */
- if (oob && ops->ooboffs && (ops->ooboffs + ops->ooblen > oobmaxlen))
- return -EINVAL;
+ if (oob && ops->ooboffs && (ops->ooboffs + ops->ooblen > oobmaxlen)) {
+ ret = -EINVAL;
+ goto err_out;
+ }
while (1) {
int bytes = mtd->writesize;
@@ -2253,6 +2260,9 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
ops->retlen = ops->len - writelen;
if (unlikely(oob))
ops->oobretlen = ops->ooblen;
+
+err_out:
+ chip->select_chip(mtd, -1);
return ret;
}
@@ -2379,8 +2389,10 @@ static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
/* Check, if it is write protected */
- if (nand_check_wp(mtd))
+ if (nand_check_wp(mtd)) {
+ chip->select_chip(mtd, -1);
return -EROFS;
+ }
/* Invalidate the page cache, if we write to the cached page */
if (page == chip->pagebuf)
@@ -2393,6 +2405,8 @@ static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
else
status = chip->ecc.write_oob(mtd, chip, page & chip->pagemask);
+ chip->select_chip(mtd, -1);
+
if (status)
return status;
@@ -2625,6 +2639,7 @@ erase_exit:
ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
/* Deselect and wake up anyone waiting on the device */
+ chip->select_chip(mtd, -1);
nand_release_device(mtd);
/* Do call back function */
--
1.7.0.4
There are two reasons to remove the "chip" parameter in nand_get_device():
[1] The nand_release_device() does not have the "chip" parameter.
[2] We can get the nand_chip by the mtd->priv field.
This patch removes the "chip" parameter in nand_get_device().
Signed-off-by: Huang Shijie <[email protected]>
---
drivers/mtd/nand/nand_base.c | 37 ++++++++++++++-----------------------
1 files changed, 14 insertions(+), 23 deletions(-)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 861a87d..55c2883 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -93,8 +93,7 @@ static struct nand_ecclayout nand_oob_128 = {
.length = 78} }
};
-static int nand_get_device(struct nand_chip *chip, struct mtd_info *mtd,
- int new_state);
+static int nand_get_device(struct mtd_info *mtd, int new_state);
static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
struct mtd_oob_ops *ops);
@@ -300,7 +299,7 @@ static int nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
if (getchip) {
chipnr = (int)(ofs >> chip->chip_shift);
- nand_get_device(chip, mtd, FL_READING);
+ nand_get_device(mtd, FL_READING);
/* Select the NAND device */
chip->select_chip(mtd, chipnr);
@@ -382,7 +381,7 @@ static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
struct mtd_oob_ops ops;
loff_t wr_ofs = ofs;
- nand_get_device(chip, mtd, FL_WRITING);
+ nand_get_device(mtd, FL_WRITING);
ops.datbuf = NULL;
ops.oobbuf = buf;
@@ -749,15 +748,15 @@ static void panic_nand_get_device(struct nand_chip *chip,
/**
* nand_get_device - [GENERIC] Get chip for selected access
- * @chip: the nand chip descriptor
* @mtd: MTD device structure
* @new_state: the state which is requested
*
* Get the device and lock it for exclusive access
*/
static int
-nand_get_device(struct nand_chip *chip, struct mtd_info *mtd, int new_state)
+nand_get_device(struct mtd_info *mtd, int new_state)
{
+ struct nand_chip *chip = mtd->priv;
spinlock_t *lock = &chip->controller->lock;
wait_queue_head_t *wq = &chip->controller->wq;
DECLARE_WAITQUEUE(wait, current);
@@ -933,7 +932,7 @@ int nand_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
if (ofs + len == mtd->size)
len -= mtd->erasesize;
- nand_get_device(chip, mtd, FL_UNLOCKING);
+ nand_get_device(mtd, FL_UNLOCKING);
/* Shift to get chip number */
chipnr = ofs >> chip->chip_shift;
@@ -983,7 +982,7 @@ int nand_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
if (check_offs_len(mtd, ofs, len))
ret = -EINVAL;
- nand_get_device(chip, mtd, FL_LOCKING);
+ nand_get_device(mtd, FL_LOCKING);
/* Shift to get chip number */
chipnr = ofs >> chip->chip_shift;
@@ -1581,11 +1580,10 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
static int nand_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, uint8_t *buf)
{
- struct nand_chip *chip = mtd->priv;
struct mtd_oob_ops ops;
int ret;
- nand_get_device(chip, mtd, FL_READING);
+ nand_get_device(mtd, FL_READING);
ops.len = len;
ops.datbuf = buf;
ops.oobbuf = NULL;
@@ -1832,7 +1830,6 @@ static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
static int nand_read_oob(struct mtd_info *mtd, loff_t from,
struct mtd_oob_ops *ops)
{
- struct nand_chip *chip = mtd->priv;
int ret = -ENOTSUPP;
ops->retlen = 0;
@@ -1844,7 +1841,7 @@ static int nand_read_oob(struct mtd_info *mtd, loff_t from,
return -EINVAL;
}
- nand_get_device(chip, mtd, FL_READING);
+ nand_get_device(mtd, FL_READING);
switch (ops->mode) {
case MTD_OPS_PLACE_OOB:
@@ -2314,11 +2311,10 @@ static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
static int nand_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const uint8_t *buf)
{
- struct nand_chip *chip = mtd->priv;
struct mtd_oob_ops ops;
int ret;
- nand_get_device(chip, mtd, FL_WRITING);
+ nand_get_device(mtd, FL_WRITING);
ops.len = len;
ops.datbuf = (uint8_t *)buf;
ops.oobbuf = NULL;
@@ -2424,7 +2420,6 @@ static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
static int nand_write_oob(struct mtd_info *mtd, loff_t to,
struct mtd_oob_ops *ops)
{
- struct nand_chip *chip = mtd->priv;
int ret = -ENOTSUPP;
ops->retlen = 0;
@@ -2436,7 +2431,7 @@ static int nand_write_oob(struct mtd_info *mtd, loff_t to,
return -EINVAL;
}
- nand_get_device(chip, mtd, FL_WRITING);
+ nand_get_device(mtd, FL_WRITING);
switch (ops->mode) {
case MTD_OPS_PLACE_OOB:
@@ -2529,7 +2524,7 @@ int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
return -EINVAL;
/* Grab the lock and see if the device is available */
- nand_get_device(chip, mtd, FL_ERASING);
+ nand_get_device(mtd, FL_ERASING);
/* Shift to get first page */
page = (int)(instr->addr >> chip->page_shift);
@@ -2675,12 +2670,10 @@ erase_exit:
*/
static void nand_sync(struct mtd_info *mtd)
{
- struct nand_chip *chip = mtd->priv;
-
pr_debug("%s: called\n", __func__);
/* Grab the lock and see if the device is available */
- nand_get_device(chip, mtd, FL_SYNCING);
+ nand_get_device(mtd, FL_SYNCING);
/* Release it and go back */
nand_release_device(mtd);
}
@@ -2766,9 +2759,7 @@ static int nand_onfi_get_features(struct mtd_info *mtd, struct nand_chip *chip,
*/
static int nand_suspend(struct mtd_info *mtd)
{
- struct nand_chip *chip = mtd->priv;
-
- return nand_get_device(chip, mtd, FL_PM_SUSPENDED);
+ return nand_get_device(mtd, FL_PM_SUSPENDED);
}
/**
--
1.7.0.4
On Mon, 2012-11-19 at 14:43 +0800, Huang Shijie wrote:
> The nand_get_device() does not select the chip, but nand_release_device()
> does de-select the chip. It is really strange.
>
> With the current code, nand_sync() will de-select the chip, even if the chip
> has never been selected.
>
> To make the balance of select/de-select chip, it's better to remove the
> de-select chip code in nand_release_device() which makes the code more
> clear.
>
> Signed-off-by: Huang Shijie <[email protected]>
Pushed to l2-mtd.git, thanks!
--
Best Regards,
Artem Bityutskiy