Messages in this thread | | | Date | Sun, 2 Nov 2014 22:03:53 +0100 | From | Frans Klaver <> | Subject | Re: [PATCH 01/27] mtd: nand: introduce function to fix a common bug in most nand-drivers not showing a device in sysfs |
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On Wed, May 28, 2014 at 01:43:44AM -0700, Brian Norris wrote: > And in fact, if any drivers are missing mtd->name, perhaps it's best to > just modify the MTD registration to give them a default: > > if (!mtd->name) > mtd->name = dev_name(&pdev->dev); >
...
> How about we rethink the "helper" approach, and instead just do > validation in the core code? This would cover most of the important > parts of your helper, I think: > > diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c > index d201feeb3ca6..39ba5812a5a3 100644 > --- a/drivers/mtd/mtdcore.c > +++ b/drivers/mtd/mtdcore.c > @@ -397,6 +397,11 @@ int add_mtd_device(struct mtd_info *mtd) > if (device_register(&mtd->dev) != 0) > goto fail_added; > > + if (mtd->dev.parent) > + mtd->owner = mtd->dev.parent->driver->owner; > + else > + WARN_ON(1); > +
So I've picked this up now. I do largely agree with the suggested approach where the validation and default settings are done in the core code. There is a problem with this, though. There are MTD devices that call mtd_device_parse_register() in the _init() function (such as the maps drivers). These don't have a device ready to be used as parent, and they would always be throwing this warning.
So either not having a parent device is bad, or it isn't. The comment suggests it is, the existing code suggests it isn't. So we'll need to make a decision about who's right.
> if (MTD_DEVT(i)) > device_create(&mtd_class, mtd->dev.parent, > MTD_DEVT(i) + 1, > diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c > index 1ca9aec141ff..9869bbef50cf 100644 > --- a/drivers/mtd/mtdpart.c > +++ b/drivers/mtd/mtdpart.c > @@ -370,7 +370,6 @@ static struct mtd_part *allocate_partition(struct mtd_info *master, > slave->mtd.subpage_sft = master->subpage_sft; > > slave->mtd.name = name; > - slave->mtd.owner = master->owner;
What would be the purpose of removing this line? Owner is already set? Can we rely on that?
Thanks, Frans
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