Hi Miquèl,
On 20/08/21 5:44 pm, Miquel Raynal wrote:
Hi Apurva,
Apurva Nandan <a-nandan@xxxxxx> wrote on Fri, 20 Aug 2021 16:56:50
+0530:
On 07/08/21 12:31 am, Miquel Raynal wrote:
Hi Apurva,
Apurva Nandan <a-nandan@xxxxxx> wrote on Tue, 13 Jul 2021 13:05:33
+0000:
The SPI NAND core doesn't know how to switch the flash to Octal DTR
mode (i.e. which operations to perform). If the manufacturer hasn't
implemented the octal_dtr_enable() manufacturer_op, the SPI NAND core
wouldn't be able to switch to 8D-8D-8D mode and will also not be able
to run in 1S-1S-1S mode due to already selected 8D-8D-8D read/write
cache op_templates.
So, avoid choosing a Octal DTR SPI op_template for read_cache,
write_cache and update_cache operations, if the manufacturer_op
octal_dtr_enable() is missing.
After looking at your previous commit I don't see why this patch would
be needed. octal_dtr_enable() only updates the mode when it succeeds so
I don't think this patch is really needed.
I added it to prevent any errors happening dues to a missing implementation of octal_dtr_enable() from manufacturer driver side.
So, if the manufacturers skips the octal_dtr_enable() implementation, we want the spinand core to run in 1s-1s-1s mode.
I still don't get the point: you fail the probe if the octal bit is
enabled but the manufacturer did not implement octal_dtr_enable(), so
how could we have issues? Maybe I am overlooking something though, but
this seemed completely redundant to my eyes so far.
Okay, I feel this may be redundant. This is for the case when the
manufacturer has added Octal DTR read/write/update cache variants but
hasn't implemented the octal_dtr_enable() method.
Without this patch, the probe would fail, if the manufacturer did not
implement octal_dtr_enable(). But after using this patch, spinand can
still use the chip in 1s-1s-1s mode in that case and just skip the Octal
DTR op variants during the selection. And also the probe would succeed.
Read/write/update op variant selection happens in select_op_variant(), much before octal_dtr_enable(). So just check if there is a definition of octal_dtr_enable in manufacturer ops and then only use 8D op variants.
Removing this wouldn't break anything in the current implementation.
Do you think we should drop this?
Signed-off-by: Apurva Nandan <a-nandan@xxxxxx>
---
drivers/mtd/nand/spi/core.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 19d8affac058..8711e887b795 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -1028,6 +1028,8 @@ static int spinand_manufacturer_match(struct spinand_device *spinand,
if (id[0] != manufacturer->id)
continue;
>> + spinand->manufacturer = manufacturer;
+
ret = spinand_match_and_init(spinand,
manufacturer->chips,
manufacturer->nchips,
@@ -1035,7 +1037,6 @@ static int spinand_manufacturer_match(struct spinand_device *spinand,
if (ret < 0)
continue;
>> - spinand->manufacturer = manufacturer;
return 0;
}
return -ENOTSUPP;
@@ -1097,6 +1098,10 @@ spinand_select_op_variant(struct spinand_device *spinand,
unsigned int nbytes;
int ret;
>> + if (spinand_op_is_octal_dtr(&op) &&
+ !spinand->manufacturer->ops->octal_dtr_enable)
+ continue;
+
nbytes = nanddev_per_page_oobsize(nand) +
nanddev_page_size(nand);
> > Thanks,
Miquèl
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Thanks,
Apurva Nandan
Thanks,
Miquèl
Thanks,
Apurva Nandan
