Re: [PATCH 1/2] mtd: nand: Drop mtd.owner requirement in nand_scan

Ezequiel Garcia
2016-04-01T22:06:51Z

On 1 April 2016 at 18:57, Richard Weinberger <richard@nod.at> wrote:
> Am 01.04.2016 um 23:29 schrieb Ezequiel Garcia:
>> Since commit 807f16d4db95 ("mtd: core: set some defaults
>> when dev.parent is set"), it's now legal for drivers
>> to call nand_scan and nand_scan_ident without setting
>> mtd.owner.
>>
>> Drop the check and while at it remove the BUG() abuse.
>>
>> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
>> ---
>> drivers/mtd/nand/nand_base.c | 10 +---------
>> 1 file changed, 1 insertion(+), 9 deletions(-)
>>
>> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
>> index c3733a10a6e7..befa04ef4a04 100644
>> --- a/drivers/mtd/nand/nand_base.c
>> +++ b/drivers/mtd/nand/nand_base.c
>> @@ -4013,7 +4013,6 @@ static int nand_dt_init(struct nand_chip *chip)
>> * This is the first phase of the normal nand_scan() function. It reads the
>> * flash ID and sets up MTD fields accordingly.
>> *
>> - * The mtd->owner field must be set to the module of the caller.
>> */
>> int nand_scan_ident(struct mtd_info *mtd, int maxchips,
>> struct nand_flash_dev *table)
>> @@ -4433,19 +4432,12 @@ EXPORT_SYMBOL(nand_scan_tail);
>> *
>> * This fills out all the uninitialized function pointers with the defaults.
>> * The flash ID is read and the mtd/chip structures are filled with the
>> - * appropriate values. The mtd->owner field must be set to the module of the
>> - * caller.
>> + * appropriate values.
>> */
>> int nand_scan(struct mtd_info *mtd, int maxchips)
>> {
>> int ret;
>>
>> - /* Many callers got this wrong, so check for it for a while... */
>> - if (!mtd->owner && caller_is_module()) {
>> - pr_crit("%s called with NULL mtd->owner!\n", __func__);
>> - BUG();
>> - }
>
> Look okay to me.
> Do we have an in-kernel user which currently hits this condition?
>

I think that (after the recent mtd.owner swept) all the drivers that
use nand_scan, will hit this condition if built as modules.
--
Ezequiel García, VanguardiaSur