[PATCH v2] mtd: gpmi: add NAND write verify support
Huang Shijie
shijie8 at gmail.com
Sat Aug 11 11:25:28 EDT 2012
Add NAND write verify support in gpmi-nand driver.
This patch fixes a kernel crash when we select
CONFIG_MTD_NAND_VERIFY_WRITE=y, and do some write tests:
root at freescale /$ dd if=/dev/zero of=/dev/mtd0 bs=128k count=1
[ 41.070000] Unable to handle kernel NULL pointer dereference at virtual addr0
[ 41.080000] pgd = c77ac000
[ 41.080000] [00000000] *pgd=4773c831, *pte=00000000, *ppte=00000000
[ 41.090000] Internal error: Oops: 17 [#1] ARM
[ 41.090000] Modules linked in:
[ 41.090000] CPU: 0 Not tainted (3.6.0-rc1-next-20120809-00002-ga25d017-d)
[ 41.090000] PC is at nand_verify_buf+0x18/0x5c
[ 41.090000] LR is at nand_write_page+0xc0/0x140
[ 41.090000] pc : [<c023e7d4>] lr : [<c023fcfc>] psr: 20000013
[ 41.090000] sp : c7779de4 ip : 00000000 fp : c6e60000
[ 41.090000] r10: 00000000 r9 : 00020000 r8 : 00000000
[ 41.090000] r7 : 00000000 r6 : c6e60000 r5 : c762cb10 r4 : 00000000
[ 41.090000] r3 : c762c8a8 r2 : 00000800 r1 : c6e60000 r0 : 00000000
[ 41.090000] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
[ 41.090000] Control: 0005317f Table: 477ac000 DAC: 00000015
[ 41.090000] Process dd (pid: 427, stack limit = 0xc7778270)
[ 41.090000] Stack: (0xc7779de4 to 0xc777a000)
...
Cc: <stable at vger.kernel.org>
Signed-off-by: Huang Shijie <shijie8 at gmail.com>
---
change log:
[1] use the mtd->writesize to allocate the verify buffer.
[2] add new field `verify_buf` in gpmi_nand_data{}
tested this patch on imx6q-arm2 board.
---
drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 23 +++++++++++++++++++++++
drivers/mtd/nand/gpmi-nand/gpmi-nand.h | 1 +
2 files changed, 24 insertions(+), 0 deletions(-)
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
index 8c0d2f0..d98bdea 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
@@ -1512,12 +1512,34 @@ static int gpmi_pre_bbt_scan(struct gpmi_nand_data *this)
return nand_boot_init(this);
}
+static int gpmi_verify_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
+{
+ struct nand_chip *chip = mtd->priv;
+ struct gpmi_nand_data *this = chip->priv;
+ int ret;
+
+ ret = chip->ecc.read_page(mtd, chip, this->verify_buf, 0, 0);
+ if (ret)
+ return -EFAULT;
+ if (memcmp(buf, this->verify_buf, len))
+ return -EFAULT;
+ return 0;
+}
+
static int gpmi_scan_bbt(struct mtd_info *mtd)
{
struct nand_chip *chip = mtd->priv;
struct gpmi_nand_data *this = chip->priv;
int ret;
+ /*
+ * We have gotten the right page size now, use it to allocate
+ * the proper verify buffer.
+ */
+ this->verify_buf = kzalloc(mtd->writesize, GFP_KERNEL);
+ if (!this->verify_buf)
+ return -ENOMEM;
+
/* Prepare for the BBT scan. */
ret = gpmi_pre_bbt_scan(this);
if (ret)
@@ -1556,6 +1578,7 @@ static int __devinit gpmi_nfc_init(struct gpmi_nand_data *this)
chip->read_byte = gpmi_read_byte;
chip->read_buf = gpmi_read_buf;
chip->write_buf = gpmi_write_buf;
+ chip->verify_buf = gpmi_verify_buf;
chip->ecc.read_page = gpmi_ecc_read_page;
chip->ecc.write_page = gpmi_ecc_write_page;
chip->ecc.read_oob = gpmi_ecc_read_oob;
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
index 1547a60..8ddf115 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
@@ -144,6 +144,7 @@ struct gpmi_nand_data {
/* MTD / NAND */
struct nand_chip nand;
struct mtd_info mtd;
+ uint8_t *verify_buf;
/* General-use Variables */
int current_chip;
--
1.7.4.4
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