于 2013年11月12日 11:44, Fabio Estevam 写道:
On Tue, Nov 12, 2013 at 12:47 AM, Huang Shijie<b32955@xxxxxxxxxxxxx> wrote:
于 2013年11月12日 02:23, Brian Norris 写道:
For imx23, the work flow is like this:
[1] first check the fingerprint, if we can find it, we will return
immediately.
[2] if [1] failed, such as you erase all the partitions, the gpmi will call
mx23_write_transcription_stamp() to write the fingerprint.
So the @chip->buffer is not only used by the
mx23_check_transcription_stamp(),
but _also_ used by the mx23_write_transcription_stamp() when the gpmi
can not find any
fingerprint in the NAND page.
That's why i use the NAND_OWN_BUFFERS, the buffer can be used by both
the mx23_check_transcription_stamp()
and mx23_write_transcription_stamp().
Understood.
What if we just allocate the 4-byte buffer once on probe?
Like this:
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
index a9830ff..647da1b 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
@@ -1342,7 +1342,6 @@ static int mx23_check_transcription_stamp(struct
gpmi_nand_data *this)
unsigned int search_area_size_in_strides;
unsigned int stride;
unsigned int page;
- uint8_t *buffer = chip->buffers->databuf;
int saved_chip_number;
int found_an_ncb_fingerprint = false;
@@ -1368,10 +1367,10 @@ static int
mx23_check_transcription_stamp(struct gpmi_nand_data *this)
* and starts in the 12th byte of the page.
*/
chip->cmdfunc(mtd, NAND_CMD_READ0, 12, page);
- chip->read_buf(mtd, buffer, strlen(fingerprint));
+ chip->read_buf(mtd, this->buffer, strlen(fingerprint));
/* Look for the fingerprint. */
- if (!memcmp(buffer, fingerprint, strlen(fingerprint))) {
+ if (!memcmp(this->buffer, fingerprint, strlen(fingerprint))) {
found_an_ncb_fingerprint = true;
break;
}
@@ -1401,7 +1400,6 @@ static int mx23_write_transcription_stamp(struct
gpmi_nand_data *this)
unsigned int block;
unsigned int stride;
unsigned int page;
- uint8_t *buffer = chip->buffers->databuf;
int saved_chip_number;
int status;
@@ -1442,9 +1440,9 @@ static int mx23_write_transcription_stamp(struct
gpmi_nand_data *this)
}
/* Write the NCB fingerprint into the page buffer. */
- memset(buffer, ~0, mtd->writesize);
+ memset(this->buffer, ~0, mtd->writesize);
memset(chip->oob_poi, ~0, mtd->oobsize);
NULL pointer here, since chip->oob_poi is NULL.
- memcpy(buffer + 12, fingerprint, strlen(fingerprint));
+ memcpy(this->buffer + 12, fingerprint, strlen(fingerprint));
/* Loop through the first search area, writing NCB fingerprints. */
dev_dbg(dev, "Writing NCB fingerprints...\n");
@@ -1455,7 +1453,7 @@ static int mx23_write_transcription_stamp(struct
gpmi_nand_data *this)
/* Write the first page of the current stride. */
dev_dbg(dev, "Writing an NCB fingerprint in page 0x%x\n", page);
chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
- chip->ecc.write_page_raw(mtd, chip, buffer, 0);
+ chip->ecc.write_page_raw(mtd, chip, this->buffer, 0);
NULL pointer here.
thanks
Huang Shijie
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