| Message ID | 20180509071358.12157-1-boris.brezillon@bootlin.com |
|---|---|
| State | Accepted |
| Delegated to: | Boris Brezillon |
| Headers | show |
| Series | mtd: rawnand: marvell: Fix read logic for layouts with ->nchunks > 2 | expand |
Hi Boris, On Wed, 9 May 2018 09:13:58 +0200, Boris Brezillon <boris.brezillon@bootlin.com> wrote: > The code is doing monolithic reads for all chunks except the last one > which is wrong since a monolithic read will issue the > READ0+ADDRS+READ_START sequence. It not only takes longer because it > forces the NAND chip to reload the page content into its internal > cache, but by doing that we also reset the column pointer to 0, which > means we'll always read the first chunk instead of moving to the next > one. > > Rework the code to do a monolithic read only for the first chunk, > then switch to naked reads for all intermediate chunks and finally > issue a last naked read for the last chunk. > > Fixes: 02f26ecf8c77 mtd: nand: add reworked Marvell NAND controller driver > Cc: stable@vger.kernel.org > Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz> > Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> > Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz> > --- I'm surprised not to have spotted this while testing the 4k pages-8b/512B strength layout. Probably something I changed during the review process and forgot to test again. Acked-by: Miquel Raynal <miquel.raynal@bootlin.com> Thanks, Miquèl
On Mon, 14 May 2018 10:38:19 +0200 Miquel Raynal <miquel.raynal@bootlin.com> wrote: > Hi Boris, > > On Wed, 9 May 2018 09:13:58 +0200, Boris Brezillon > <boris.brezillon@bootlin.com> wrote: > > > The code is doing monolithic reads for all chunks except the last one > > which is wrong since a monolithic read will issue the > > READ0+ADDRS+READ_START sequence. It not only takes longer because it > > forces the NAND chip to reload the page content into its internal > > cache, but by doing that we also reset the column pointer to 0, which > > means we'll always read the first chunk instead of moving to the next > > one. > > > > Rework the code to do a monolithic read only for the first chunk, > > then switch to naked reads for all intermediate chunks and finally > > issue a last naked read for the last chunk. > > > > Fixes: 02f26ecf8c77 mtd: nand: add reworked Marvell NAND controller driver > > Cc: stable@vger.kernel.org > > Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz> > > Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> > > Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz> > > --- > > I'm surprised not to have spotted this while testing the 4k > pages-8b/512B strength layout. Probably something I changed during the > review process and forgot to test again. > > Acked-by: Miquel Raynal <miquel.raynal@bootlin.com> Applied.
diff --git a/drivers/mtd/nand/raw/marvell_nand.c b/drivers/mtd/nand/raw/marvell_nand.c index db5ec4e8bde9..ebb1d141b900 100644 --- a/drivers/mtd/nand/raw/marvell_nand.c +++ b/drivers/mtd/nand/raw/marvell_nand.c @@ -1194,11 +1194,13 @@ static void marvell_nfc_hw_ecc_bch_read_chunk(struct nand_chip *chip, int chunk, NDCB0_CMD2(NAND_CMD_READSTART); /* - * Trigger the naked read operation only on the last chunk. - * Otherwise, use monolithic read. + * Trigger the monolithic read on the first chunk, then naked read on + * intermediate chunks and finally a last naked read on the last chunk. */ - if (lt->nchunks == 1 || (chunk < lt->nchunks - 1)) + if (chunk == 0) nfc_op.ndcb[0] |= NDCB0_CMD_XTYPE(XTYPE_MONOLITHIC_RW); + else if (chunk < lt->nchunks - 1) + nfc_op.ndcb[0] |= NDCB0_CMD_XTYPE(XTYPE_NAKED_RW); else nfc_op.ndcb[0] |= NDCB0_CMD_XTYPE(XTYPE_LAST_NAKED_RW);