Messages in this thread | | | Subject | Re: [PATCH 08/13] mtd: spinand: Reject 8D-8D-8D op_templates if octal_dtr_enale() is missing in manufacturer_op | From | Apurva Nandan <> | Date | Fri, 20 Aug 2021 19:24:34 +0530 |
| |
Hi Miquèl,
On 20/08/21 5:44 pm, Miquel Raynal wrote: > Hi Apurva, > > Apurva Nandan <a-nandan@ti.com> 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@ti.com> 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@ti.com> >>>> --- >>>> 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 >>> >>> ______________________________________________________ >>> Linux MTD discussion mailing list >>> http://lists.infradead.org/mailman/listinfo/linux-mtd/ >>> >> >> Thanks, >> Apurva Nandan > > > > > Thanks, > Miquèl >
Thanks, Apurva Nandan
| |