From patchwork Sun Aug 12 02:07:55 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [v4] mtd: gpmi: add NAND write verify support Date: Sat, 11 Aug 2012 16:07:55 -0000 From: Huang Shijie X-Patchwork-Id: 176689 Message-Id: <1344737275-18342-1-git-send-email-shijie8@gmail.com> To: dwmw2@infradead.org Cc: marex@denx.de, fabio.estevam@freescale.com, dedekind1@gmail.com, stable@vger.kernel.org, linux-mtd@lists.infradead.org, shawn.guo@linaro.org, Huang Shijie , linux-arm-kernel@lists.infradead.org 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 : [] lr : [] 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) ... The crash log is fetched from Fabio's patch. thanks to Fabio's hard work. Cc: Reported-by: Fabio Estevam Signed-off-by: Huang Shijie --- v3 --> v4: [1] add credit to Fabio. 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); + 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); + 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;