Messages in this thread | | | Date | Wed, 17 Apr 2024 16:52:42 +0200 | From | "Michael Walle" <> | Subject | Re: [RFC PATCH v1 6/6] mtd: spi-nor: introduce support for displaying deprecation message |
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Hi,
On Wed Apr 17, 2024 at 4:36 PM CEST, Pratyush Yadav wrote: > On Fri, Apr 12 2024, Michael Walle wrote: > > > SPI-NOR will automatically detect the attached flash device most of the > > time. We cannot easily find out if boards are using a given flash. > > Therefore, introduce a (temporary) flag to display a message on boot if > > Why temporary? There will always be a need to deprecate one flash or > another. Might as well keep the flag around.
Mh, yes I agree. That also means that this flag will not have any users (most) of the time (hopefully ;) ).
> Also, this patch/series does not add any users of the deprecated flag. > If you have some flashes in mind, it would be good to add them to the > patch/series.
This is just an RFC to see if whether you Tudor agree with me :) But I was about to add it to the evervision/cypress FRAMs.
> I like the idea in general. Do you think we should also print a rough > date for the deprecation as well?
Might make sense, any suggestions?
> > support for a given flash device is scheduled to be removed in the > > future. > > > > Signed-off-by: Michael Walle <mwalle@kernel.org> > > --- > > drivers/mtd/spi-nor/core.c | 12 ++++++++++++ > > drivers/mtd/spi-nor/core.h | 1 + > > 2 files changed, 13 insertions(+) > > > > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c > > index 58d310427d35..a294eef2e34a 100644 > > --- a/drivers/mtd/spi-nor/core.c > > +++ b/drivers/mtd/spi-nor/core.c > > @@ -3312,6 +3312,7 @@ static const struct flash_info *spi_nor_get_flash_info(struct spi_nor *nor, > > const char *name) > > { > > const struct flash_info *jinfo = NULL, *info = NULL; > > + const char *deprecated = NULL; > > > > if (name) > > info = spi_nor_match_name(nor, name); > > @@ -3326,6 +3327,17 @@ static const struct flash_info *spi_nor_get_flash_info(struct spi_nor *nor, > > return jinfo; > > } > > > > + if (info && (info->flags & SPI_NOR_DEPRECATED)) > > + deprecated = info->name; > > + else if (jinfo && (jinfo->flags & SPI_NOR_DEPRECATED)) > > + deprecated = jinfo->name; > > + > > + if (deprecated) > > + pr_warn("Your board or device tree is using a SPI NOR flash (%s) with\n" > > + "deprecated driver support. It will be removed in future kernel\n" > > Nit: "removed in a future kernel version" > > > + "version. If you feel this shouldn't be the case, please contact\n" > > + "us at linux-mtd@lists.infradead.org\n", deprecated); > > + > > Hmm, this isn't so nice. I'd suggest doing something like: > > /* > * If caller has specified name of flash model that can normally be > * ... > */ > info = jinfo ?: info; > > if (info->flags & SPI_NOR_DEPRECATED) > pr_warn(...);
Actually, I had that, *but* I was thinking we might only check the detected flash and not the one specified in the device tree. But thinking about that again, I guess it makes sense because: - that's the actually used flash driver - having jinfo != info will print that other warning, thus this case is hopefully very unlikely.
> > return info; > > > /* > > * If caller has specified name of flash model that can normally be > > * detected using JEDEC, let's verify it. > > diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h > > index 8552e31b1b07..0317d8e253f4 100644 > > --- a/drivers/mtd/spi-nor/core.h > > +++ b/drivers/mtd/spi-nor/core.h > > @@ -524,6 +524,7 @@ struct flash_info { > > #define SPI_NOR_NO_ERASE BIT(6) > > #define SPI_NOR_QUAD_PP BIT(8) > > #define SPI_NOR_RWW BIT(9) > > +#define SPI_NOR_DEPRECATED BIT(15) > > If you do agree with my suggestion of making it permanent, would it make > more sense to make it BIT(10) instead. Or BIT(9) once you move up the > others because we no longer have BIT(7).
Or just BIT(7) and avoid any code churn :)
-michael
> > > > > u8 no_sfdp_flags; > > #define SPI_NOR_SKIP_SFDP BIT(0)
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