On Mon, Apr 22, 2013 at 12:47 AM, Huang Shijie<b32955@xxxxxxxxxxxxx> wrote:I not sure who will uses ecc_strength/ecc_size, except the gpmi.Since the ONFI 2.1, the onfi spec adds the Extended Parameter PageI think we want a return code (int) for this function. It obviously
to store the ECC info.
The onfi spec tells us that if the nand chip's recommended ECC codeword
size is not 512 bytes, then the @ecc_bits is 0xff. The host _SHOULD_ then
read the Extended ECC information that is part of the extended parameter
page to retrieve the ECC requirements for this device.
This patch implement the reading of the Extended Parameter Page, and parses
the sections for ECC type, and get the ECC info from the ECC section.
Tested this patch with Micron MT29F64G08CBABAWP.
Signed-off-by: Huang Shijie<b32955@xxxxxxxxxxxxx>
---
drivers/mtd/nand/nand_base.c | 54 ++++++++++++++++++++++++++++++++++++++++++
1 files changed, 54 insertions(+), 0 deletions(-)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index beff911..48ff097 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2846,6 +2846,56 @@ static u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
return crc;
}
+/* Parse the Extended Parameter Page. */
+static void nand_flash_detect_ext_param_page(struct mtd_info *mtd,
+ struct nand_chip *chip, struct nand_onfi_params *p, int last)
+{
can fail, and the caller needs to know this.
The "last" parameter is not very obvious until you read the wholeok. I can add more comments.
function, where you see that this function assumes a lot about the
caller. Please address the comments below and/or fully document the
parameters and calling context for this function.
You can give me a fix patch which bases on my patch set.+ struct onfi_ext_param_page *ep;Why not?
+ struct onfi_ext_section *s;
+ struct onfi_ext_ecc_info *ecc;
+ uint8_t *cursor;
+ int len;
+ int i;
+
+ len = le16_to_cpu(p->ext_param_page_length) * 16;
+ ep = kcalloc(1, max_t(int, len, sizeof(*p)), GFP_KERNEL);
+ if (!ep)
+ goto ext_out;
+
+ /*
+ * Skip the ONFI Parameter Pages.
+ * The Change Read Columm command may does not works here.
we have sent a command in the nand_flash_detect_onfi().+ */You never sent a command to the chip. How can you expect to read from it?
+ for (i = last + 1; i< p->num_of_param_pages; i++)
+ chip->read_buf(mtd, (uint8_t *)ep, sizeof(*p));
It seems that you are writing this function with the assumption of aI added the "last" argument just because the Change-read-column command did not works.
particular calling context (a context in which the last command was
CMD_PARAM). IMO, it would make a lot more sense that this function
actually send its own CMD_PARAM followed by either X bytes of skipped
read_buf() or a change read column command. Then it doesn't need the
"last" argument, and its usage makes much more sense.