On Wed, Sep 12, 2012 at 10:26:05PM -0000, Prabhakar Kushwaha wrote:
IFC-1.1.0 uses 28nm techenology for SRAM. This tech has known limitaion for SRAM i.e. "byte select" is not supported. Hence Read Modify Write is implemented in IFC for any "system side write" into sram buffer. Reading an uninitialized memory results in ECC Error from sram wrapper.
Hence we must initialize/prefill SRAM buffer by any data before writing anything in SRAM from system side. To initialize SRAM user can use "READID" NAND command with read bytes equal to SRAM size. It will be a one time activity post boot
Signed-off-by: Prabhakar Kushwaha prabhakar@freescale.com
Based upon git://git.denx.de/u-boot.git (branch master)
This patchs depends upon following patch http://patchwork.ozlabs.org/patch/178332/
drivers/mtd/nand/fsl_ifc_nand.c | 62 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 61 insertions(+), 1 deletion(-)
diff --git a/drivers/mtd/nand/fsl_ifc_nand.c b/drivers/mtd/nand/fsl_ifc_nand.c index a518526..140fdc7 100644 --- a/drivers/mtd/nand/fsl_ifc_nand.c +++ b/drivers/mtd/nand/fsl_ifc_nand.c @@ -30,6 +30,7 @@ #include <asm/errno.h> #include <asm/fsl_ifc.h>
+#define FSL_IFC_V1_1_0 0x01010000 #define MAX_BANKS 4 #define ERR_BYTE 0xFF /* Value returned for read bytes when read failed */ @@ -738,11 +739,66 @@ static void fsl_ifc_select_chip(struct mtd_info *mtd, int chip) { }
+static void fsl_ifc_sram_init()
fsl_ifc_nand.c:742:13: warning: function declaration isn't a prototype
Fixed and applied to u-boot-nand-flash
-Scott