In some cases, nand_do_{read,write}_ops is passed with unaligned ops->datbuf. Drivers using DMA will be unhappy about unaligned buffer.
The new struct member, buf_align, represents the minimum alignment the driver require for the buffer. If the buffer passed from the upper MTD layer does not have enough alignment, nand_do_*_ops will use bufpoi.
Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com
[Linux commit: 477544c62a84d3bacd9f90ba75ffc16c04d78071]
---
drivers/mtd/nand/nand_base.c | 8 ++++++++ include/linux/mtd/nand.h | 2 ++ 2 files changed, 10 insertions(+)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 16d4554..f3c515b 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -1720,6 +1720,9 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
if (!aligned) use_bufpoi = 1; + else if (chip->options & NAND_USE_BOUNCE_BUFFER) + use_bufpoi = !IS_ALIGNED((unsigned long)buf, + chip->buf_align); else use_bufpoi = 0;
@@ -2575,6 +2578,9 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
if (part_pagewr) use_bufpoi = 1; + else if (chip->options & NAND_USE_BOUNCE_BUFFER) + use_bufpoi = !IS_ALIGNED((unsigned long)buf, + chip->buf_align); else use_bufpoi = 0;
@@ -3119,6 +3125,8 @@ static void nand_set_defaults(struct nand_chip *chip, int busw) init_waitqueue_head(&chip->controller->wq); }
+ if (!chip->buf_align) + chip->buf_align = 1; }
/* Sanitize ONFI strings so we can safely print them */ diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index be30059..90c6010 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -752,6 +752,7 @@ nand_get_sdr_timings(const struct nand_data_interface *conf) * setting the read-retry mode. Mostly needed for MLC NAND. * @ecc: [BOARDSPECIFIC] ECC control structure * @buffers: buffer structure for read/write + * @buf_align: minimum buffer alignment required by a platform * @hwcontrol: platform-specific hardware control structure * @erase: [REPLACEABLE] erase function * @scan_bbt: [REPLACEABLE] function to scan bad block table @@ -893,6 +894,7 @@ struct nand_chip {
struct nand_ecc_ctrl ecc; struct nand_buffers *buffers; + unsigned long buf_align; struct nand_hw_control hwcontrol;
uint8_t *bbt;