[PATCH] mtd: spi-nor: stop printing superfluous debug info
Michael Walle
michael at walle.cc
Tue Nov 28 01:10:54 PST 2023
Hi,
>> > The mtd data can be obtain with the mtd ioctls and the SPI NOR
>> > flash name can be determined interrogating the sysfs entries.
>> > Stop polluting the kernel log.
>> >
>> > Signed-off-by: Tudor Ambarus <tudor.ambarus at linaro.org>
>> >
>> > ---
>> > drivers/mtd/spi-nor/core.c | 19 -------------------
>> > 1 file changed, 19 deletions(-)
>> >
>> > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
>> > index 25a64c65717d..6de76fd009d1 100644
>> > --- a/drivers/mtd/spi-nor/core.c
>> > +++ b/drivers/mtd/spi-nor/core.c
>> > @@ -3517,25 +3517,6 @@ int spi_nor_scan(struct spi_nor *nor, const char > *name,
>> > /* No mtd_info fields should be used up to this point. */
>> > spi_nor_set_mtd_info(nor);
>> >
>> > - dev_info(dev, "%s (%lld Kbytes)\n", info->name,
>> > - (long long)mtd->size >> 10);
>>
>> I'd lower this to dev_dbg() and print the jedec id. It might come in
>> handy for a quick glance during bootup if debug is enabled.
>
> Ack. Although, your boot time will almost be unaffected if you don't
> print the info messages to the console. What takes the most time is not
> writing to the kernel buffer, it's to display the lines on a serial
> console, and dev_info() are by default discarded, you need to select a
> lower log level manually, and if you do that it means you're not
> looking for quick boot times but rather more for additional
> information.
Also with recent (or planned, dunno the current state) printk won't wait
anymore for the slowest console. I really don't have a strong opinion,
either dev_info(jedec_id) or dev_dbg(jedec_id). Whatever Tudor prefers.
>> > - dev_dbg(dev,
>> > - "mtd .name = %s, .size = 0x%llx (%lldMiB), "
>> > - ".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n",
>> > - mtd->name, (long long)mtd->size, (long long)(mtd->size >> 20),
>> > - mtd->erasesize, mtd->erasesize / 1024, mtd->numeraseregions);
>> > -
>> > - if (mtd->numeraseregions)
>> > - for (i = 0; i < mtd->numeraseregions; i++)
>> > - dev_dbg(dev,
>> > - "mtd.eraseregions[%d] = { .offset = 0x%llx, "
>> > - ".erasesize = 0x%.8x (%uKiB), "
>> > - ".numblocks = %d }\n",
>> > - i, (long long)mtd->eraseregions[i].offset,
>> > - mtd->eraseregions[i].erasesize,
>> > - mtd->eraseregions[i].erasesize / 1024,
>> > - mtd->eraseregions[i].numblocks);
>> > return 0;
>>
>> Part of this is already available through the spi-nor debugfs,
>> although not
>> the actual mtd properties. These I think, should go into the mtdcore
>> itself if really needed. Either through dev_dbg() or debugfs.
>
> Maybe we don't need this at all, as long as one message remains about
> the JEDEC ID, but keep in mind that spi-nors are commonly storing the
> rootfs and if your spi-nor does not boot you don't have a userspace yet
> and all the debugfs entries are purely useless.
Good point.
Just curious, do you know any boards which has the rootfs writable on
the spi-nor flash?
-michael
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