Dear Huang Shijie, Please re-add credit to Fabio. Also, Fabio fixed the subject to be more accurate. Your subject makes this sound like it's adding a feature that can be postponed, yet this fixes a serious problem with the driver.
> 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@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: <[email protected]> > Signed-off-by: Huang Shijie <[email protected]> > --- > v2 --> v3: > [1] free the verify_buf when we exit. > > v1 --> v2: > [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 | 25 +++++++++++++++++++++++++ > drivers/mtd/nand/gpmi-nand/gpmi-nand.h | 1 + > 2 files changed, 26 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..e1e4c51 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); devm_ will work here just fine. > + if (!this->verify_buf) > + return -ENOMEM; > + > /* Prepare for the BBT scan. */ > ret = gpmi_pre_bbt_scan(this); > if (ret) > @@ -1531,6 +1553,8 @@ void gpmi_nfc_exit(struct gpmi_nand_data *this) > { > nand_release(&this->mtd); > gpmi_free_dma_buffer(this); > + kfree(this->verify_buf); Then you can drop this altogether. > + this->verify_buf = NULL; > } > > static int __devinit gpmi_nfc_init(struct gpmi_nand_data *this) > @@ -1556,6 +1580,7 @@ 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; Best regards, Marek Vasut -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
