Since we do not support sub-page writes anyway, reading the page back to the controller on SEQIN command is not required. Remove the page read on SEQIN.
However, the column/page values relevant to the SEQIN command, hence set the column/row address on SEQIN command.
Signed-off-by: Stefan Agner stefan@agner.ch --- This improved the write performance quite nicely. The nand write command improves from 2.9MiB/s to 3.5MiB/s. A ubi write of a UBIFS image which is around 100MiB improves from 34.5s to 27.1s. Measured on a Colibri VF61 (512MiB Macronix NAND).
drivers/mtd/nand/vf610_nfc.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c index fa0bb9d..66b335d 100644 --- a/drivers/mtd/nand/vf610_nfc.c +++ b/drivers/mtd/nand/vf610_nfc.c @@ -345,24 +345,26 @@ static void vf610_nfc_command(struct mtd_info *mtd, unsigned command, nfc->alt_buf = 0;
switch (command) { + case NAND_CMD_SEQIN: + /* Use valid column/page from preread... */ + vf610_nfc_addr_cycle(mtd, column, page); + /* + * SEQIN => data => PAGEPROG sequence is done by the controller + * hence we do not need to issue the command here... + */ + return; case NAND_CMD_PAGEPROG: vf610_nfc_transfer_size(nfc->regs, nfc->page_sz); vf610_nfc_send_commands(nfc->regs, NAND_CMD_SEQIN, command, PROGRAM_PAGE_CMD_CODE); - vf610_nfc_addr_cycle(mtd, column, page); break;
case NAND_CMD_RESET: vf610_nfc_transfer_size(nfc->regs, 0); vf610_nfc_send_command(nfc->regs, command, RESET_CMD_CODE); break; - /* - * NFC does not support sub-page reads and writes, - * so emulate them using full page transfers. - */ case NAND_CMD_READOOB: nfc->spareonly = 1; - case NAND_CMD_SEQIN: /* Pre-read for partial writes. */ case NAND_CMD_READ0: column = 0; vf610_nfc_transfer_size(nfc->regs, nfc->page_sz);