Re: [PATCH v5 1/2] mtd: spinand: Add support for setting plane select bits

From: Cheng Ming Lin
Date: Mon Sep 02 2024 - 21:19:17 EST


Hi Miquel,

Miquel Raynal <miquel.raynal@xxxxxxxxxxx> 於 2024年9月2日 週一 下午8:28寫道:
>
> Hi Cheng,
>
> linchengming884@xxxxxxxxx wrote on Mon, 2 Sep 2024 16:42:55 +0800:
>
> > Hi Miquel,
> >
> > I accidentally sent the previous email before it was finished.
> >
> > Miquel Raynal <miquel.raynal@xxxxxxxxxxx> 於 2024年8月30日 週五 下午11:55寫道:
> > >
> > > Hi ChengMing,
> > >
> > > linchengming884@xxxxxxxxx wrote on Fri, 30 Aug 2024 18:03:09 +0800:
> > >
> > > > From: Cheng Ming Lin <chengminglin@xxxxxxxxxxx>
> > > >
> > > > Add two flags for inserting the Plane Select bit into the column
> > > > address during the write_to_cache and the read_from_cache operation.
> > > >
> > > > Add the SPINAND_HAS_PP_PLANE_SELECT_BIT flag for serial NAND flash
> > >
> > > This flag has been renamed :)
> >
> > Thank you for the reminder. I will make the necessary changes.
> >
> > >
> > > > that require inserting the Plane Select bit into the column address
> > > > during the write_to_cache operation.
> > > >
> > > > Add the SPINAND_HAS_READ_PLANE_SELECT_BIT flag for serial NAND flash
> > > > that require inserting the Plane Select bit into the column address
> > > > during the read_from_cache operation.
> > > >
> > > > Signed-off-by: Cheng Ming Lin <chengminglin@xxxxxxxxxxx>
> > > > ---
> > > > drivers/mtd/nand/spi/core.c | 6 ++++++
> > > > include/linux/mtd/spinand.h | 2 ++
> > > > 2 files changed, 8 insertions(+)
> > > >
> > > > diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
> > > > index e0b6715e5dfe..e7b592cdbb4c 100644
> > > > --- a/drivers/mtd/nand/spi/core.c
> > > > +++ b/drivers/mtd/nand/spi/core.c
> > > > @@ -386,6 +386,9 @@ static int spinand_read_from_cache_op(struct spinand_device *spinand,
> > > > else
> > > > rdesc = spinand->dirmaps[req->pos.plane].rdesc_ecc;
> > > >
> > > > + if (spinand->flags & SPINAND_HAS_READ_PLANE_SELECT_BIT)
> > > > + column |= req->pos.plane << fls(nanddev_page_size(nand));
> > >
> > > Isn't there any better way to know what the bit position is?
> >
> > There are two other methods to determine the bit position:
> > - column |= res->pos.plane << fls(nand->memorg.pagesize)
> > - column |= wdesc->info.offset
>
> Ok, let's keep it is as-is for now.
>

Got it. I'll keep it as-is for now.

> Thanks,
> Miquèl

Thanks,
Cheng Ming Lin