On 12/03/21 08:05PM, Michael Walle wrote: > If spi_nor_read_sfdp() is used after probe, we have to set read_proto > and the read dirmap. > > Signed-off-by: Michael Walle <[email protected]> > --- > drivers/mtd/spi-nor/sfdp.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c > index b1814afefc33..47634ec9b899 100644 > --- a/drivers/mtd/spi-nor/sfdp.c > +++ b/drivers/mtd/spi-nor/sfdp.c > @@ -179,19 +179,27 @@ static int spi_nor_read_sfdp(struct spi_nor *nor, u32 > addr, > size_t len, void *buf) > { > u8 addr_width, read_opcode, read_dummy; > + struct spi_mem_dirmap_desc *rdesc; > + enum spi_nor_protocol read_proto; > int ret; > > read_opcode = nor->read_opcode; > + read_proto = nor->read_proto; > + rdesc = nor->dirmap.rdesc; > addr_width = nor->addr_width; > read_dummy = nor->read_dummy; > > nor->read_opcode = SPINOR_OP_RDSFDP; > + nor->read_proto = SNOR_PROTO_1_1_1; > + nor->dirmap.rdesc = NULL; > nor->addr_width = 3; > nor->read_dummy = 8;
NACK. You can't assume the device is still in 1S-1S-1S mode after probe. For example, the s28hs512t flash is switched to 8D-8D-8D mode by the time the probe finishes so this would be an invalid command. Same for any flash that goes into a stateful mode. And you can't even keep using nor->read_proto to read SFDP because the Read SFDP command might not be supported in all modes. xSPI spec (JESD251) says that the Read SFDP command is optional in 8D-8D-8D mode. I think the best approach for this would be to cache the entire SFDP table at parse time. This obviously comes with a memory overhead but I don't think it would be too big. For example, the sfdp table on s28hs512t is 491 bytes and it has 6 tables. Anyway, if the memory usage is too much of a problem we can put the feature behind a config. > > ret = spi_nor_read_raw(nor, addr, len, buf); > > nor->read_opcode = read_opcode; > + nor->read_proto = read_proto; > + nor->dirmap.rdesc = rdesc; > nor->addr_width = addr_width; > nor->read_dummy = read_dummy; > > -- > 2.20.1 > -- Regards, Pratyush Yadav Texas Instruments Inc.
