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mtd: nand: add 'oob_required' argument to NAND {read,write}_page interfaces

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New NAND controllers can perform read/write via HW engines which don't expose
OOB data in their DMA mode. To reflect this, we should rework the nand_chip /
nand_ecc_ctrl interfaces that assume that drivers will always read/write OOB
data in the nand_chip.oob_poi buffer. A better interface includes a boolean
argument that explicitly tells the callee when OOB data is requested by the
calling layer (for reading/writing to/from nand_chip.oob_poi).

This patch adds the 'oob_required' parameter to each relevant {read,write}_page
interface; all 'oob_required' parameters are left unused for now. The next
patch will set the parameter properly in the nand_base.c callers, and follow-up
patches will make use of 'oob_required' in some of the callee functions.

Note that currently, there is no harm in ignoring the 'oob_required' parameter
and *always* utilizing nand_chip.oob_poi, but there can be
performance/complexity/design benefits from avoiding filling oob_poi in the
common case. I will try to implement this for some drivers which can be ported
easily.

Note: I couldn't compile-test all of these easily, as some had ARCH
dependencies.

[dwmw2: Merge later 1/0 vs. true/false cleanup]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Acked-by: Jiandong Zheng <jdzheng@broadcom.com>
Acked-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Brian Norris
2012-05-02 10:14:55 -07:00
committed by David Woodhouse
parent b4f7aa84d6
commit 1fbb938dff
15 changed files with 90 additions and 72 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/mtd/nand/cafe_nand.c
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@@ -375,12 +375,13 @@ static int cafe_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
* @mtd: mtd info structure
* @chip: nand chip info structure
* @buf: buffer to store read data
* @oob_required: caller expects OOB data read to chip->oob_poi
*
* The hw generator calculates the error syndrome automatically. Therefor
* we need a special oob layout and handling.
*/
static int cafe_nand_read_page(struct mtd_info *mtd, struct nand_chip *chip,
uint8_t *buf, int page)
uint8_t *buf, int oob_required, int page)
{
struct cafe_priv *cafe = mtd->priv;
unsigned int max_bitflips = 0;
@@ -520,7 +521,8 @@ static struct nand_bbt_descr cafe_bbt_mirror_descr_512 = {
static void cafe_nand_write_page_lowlevel(struct mtd_info *mtd,
struct nand_chip *chip, const uint8_t *buf)
struct nand_chip *chip,
const uint8_t *buf, int oob_required)
{
struct cafe_priv *cafe = mtd->priv;
@@ -532,16 +534,17 @@ static void cafe_nand_write_page_lowlevel(struct mtd_info *mtd,
}
static int cafe_nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
const uint8_t *buf, int page, int cached, int raw)
const uint8_t *buf, int oob_required, int page,
int cached, int raw)
{
int status;
chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
if (unlikely(raw))
chip->ecc.write_page_raw(mtd, chip, buf);
chip->ecc.write_page_raw(mtd, chip, buf, oob_required);
else
chip->ecc.write_page(mtd, chip, buf);
chip->ecc.write_page(mtd, chip, buf, oob_required);
/*
* Cached progamming disabled for now, Not sure if its worth the