Re: [PATCH v4 03/11] mtd: spi-nor: core: Use auto-detection only once

Pratyush Yadav
2022-04-21T13:17:38Z

On 21/04/22 07:18AM, Tudor.Ambarus@microchip.com wrote:
> Hi, Pratyush,
>
> I forgot to remove few checks, would you please remove them when applying?
> See below.
>
> On 4/20/22 13:34, Tudor Ambarus wrote:
> > In case spi_nor_match_name() returned NULL, the auto detection was
> > issued twice. There's no reason to try to detect the same chip twice,
> > do the auto detection only once.
> >
> > Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> > Reviewed-by: Michael Walle <michael@walle.cc>
> > ---
> > drivers/mtd/spi-nor/core.c | 13 ++++++++-----
> > 1 file changed, 8 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> > index b9cc8bbf1f62..b55d922d46dd 100644
> > --- a/drivers/mtd/spi-nor/core.c
> > +++ b/drivers/mtd/spi-nor/core.c
> > @@ -2896,13 +2896,14 @@ static const struct flash_info *spi_nor_get_flash_info(struct spi_nor *nor,
> > {
> > const struct flash_info *info = NULL;
> >
> > - if (name)
> > + if (name) {
> > info = spi_nor_match_name(nor, name);
> > + if (IS_ERR(info))
> > + return info;
>
> As Michael suggested spi_nor_match_name() returns NULL or valid entry, so this
> check is not necessary, let's remove them.
>
> > + }
> > /* Try to auto-detect if chip name wasn't specified or not found */
> > if (!info)
> > - info = spi_nor_read_id(nor);
> > - if (IS_ERR_OR_NULL(info))
> > - return ERR_PTR(-ENOENT);
> > + return spi_nor_read_id(nor);
> >
> > /*
> > * If caller has specified name of flash model that can normally be
> > @@ -2994,7 +2995,9 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
> > return -ENOMEM;
> >
> > info = spi_nor_get_flash_info(nor, name);
> > - if (IS_ERR(info))
> > + if (!info)
> > + return -ENOENT;
>
> also according to Michael, this change is not needed as spi_nor_get_flash_info() can't
> return NULL. Here we can keep the code as it was. Let me know if you want me to respin.

TBH I don't think a NULL check here hurts much since the behaviour might
change later, and error paths don't get exercised as often. But I have
made both changes when applying. You can double-check at [0] if you
want.

[0] https://github.com/prati0100/linux-0day/commit/67d913746833ee54bf4c661040f3ef13657dffd8

>
> > + else if (IS_ERR(info))
> > return PTR_ERR(info);
> >
> > nor->info = info;
>

--
Regards,
Pratyush Yadav
Texas Instruments Inc.