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

Tudor.Ambarus
2022-04-21T13:42:48Z

On 4/21/22 16:16, Pratyush Yadav wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> 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

I agree, but at the same time we're introducing checks gratuitously. Since
Michael cared about it, it's fine that we removed it. I don't care too much
about it.

> made both changes when applying. You can double-check at [0] if you
> want.>
> [0] https://github.com/prati0100/linux-0day/commit/67d913746833ee54bf4c661040f3ef13657dffd8

looks good.

btw: I think this patch
https://github.com/prati0100/linux-0day/commit/b45bbff85d49529f8daff83c341a292f6c6492ca
may introduce a regression on some atmel chips. Let me try it please.
>
>>
>>> + else if (IS_ERR(info))
>>> return PTR_ERR(info);
>>>
>>> nor->info = info;
>>
>
> --
> Regards,
> Pratyush Yadav
> Texas Instruments Inc.