The patch titled
atmel_nand: Work around AT32AP7000 ECC errata
has been added to the -mm tree. Its filename is
atmel_nand-work-around-at32ap7000-ecc-errata.patch
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See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
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Subject: atmel_nand: Work around AT32AP7000 ECC errata
From: Haavard Skinnemoen <haavard.skinnemoen@xxxxxxxxx>
The ALE signal isn't correctly wired up to the ECC controller on the
AP7000, so it starts calculating ECC during the address cycles.
Work around this by resetting the ECC controller between the address and
data cycles.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@xxxxxxxxx>
Acked-by: Andrew Victor <linux@xxxxxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/mtd/nand/atmel_nand.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff -puN drivers/mtd/nand/atmel_nand.c~atmel_nand-work-around-at32ap7000-ecc-errata drivers/mtd/nand/atmel_nand.c
--- a/drivers/mtd/nand/atmel_nand.c~atmel_nand-work-around-at32ap7000-ecc-errata
+++ a/drivers/mtd/nand/atmel_nand.c
@@ -33,6 +33,7 @@
#include <linux/io.h>
#include <asm/arch/board.h>
+#include <asm/arch/cpu.h>
#ifdef CONFIG_MTD_NAND_ATMEL_ECC_HW
#define hard_ecc 1
@@ -264,6 +265,19 @@ static int atmel_nand_read_page(struct m
uint8_t *ecc_pos;
int stat;
+ /*
+ * Errata: ALE is incorrectly wired up to the ECC controller
+ * on the AP7000, so it will include the address cycles in the
+ * ECC calculation.
+ *
+ * Workaround: Reset the parity registers before reading the
+ * actual data.
+ */
+ if (cpu_is_at32ap7000()) {
+ struct atmel_nand_host *host = chip->priv;
+ ecc_writel(host->ecc, CR, ATMEL_ECC_RST);
+ }
+
/* read the page */
chip->read_buf(mtd, p, eccsize);
@@ -377,9 +391,16 @@ static int atmel_nand_correct(struct mtd
}
/*
- * Enable HW ECC : unsused
+ * Enable HW ECC : unused on most chips
*/
-static void atmel_nand_hwctl(struct mtd_info *mtd, int mode) { ; }
+static void atmel_nand_hwctl(struct mtd_info *mtd, int mode)
+{
+ if (cpu_is_at32ap7000()) {
+ struct nand_chip *nand_chip = mtd->priv;
+ struct atmel_nand_host *host = nand_chip->priv;
+ ecc_writel(host->ecc, CR, ATMEL_ECC_RST);
+ }
+}
#ifdef CONFIG_MTD_PARTITIONS
static const char *part_probes[] = { "cmdlinepart", NULL };
_
Patches currently in -mm which might be from haavard.skinnemoen@xxxxxxxxx are
atmel_nand-speedup-via-readwritesbw.patch
atmel_nand-work-around-at32ap7000-ecc-errata.patch
mtd-atmel_nand-can-be-modular.patch
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