Messages in this thread | | | Date | Wed, 28 May 2014 00:25:13 -0700 | From | Brian Norris <> | Subject | Re: [PATCH 09/27] mtd: nand: pxa3xx: show device structure in sysfs |
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On Tue, May 27, 2014 at 08:01:55AM +0200, Alexander Holler wrote: > Am 27.05.2014 05:12, schrieb Alexander Shiyan: > >Should we add "driver.owner = THIS_MODULE" field for struct platform_driver in this case? > > Yes. I assumed all drivers/modules already had an owner. I will > check them all and will send a v2 for those which don't have one. I > wonder what this field is used for if it works without. ;)
Looks like the mtd->owner essentially filters down to a try_module_get() (called in the get_mtd_device() API) which ensures that MTD users (e.g., mtdblock, UBI, etc.) hold a refcount on the driver module. If the owner is not set properly by a driver, then try_module_get() just does a silent no-op, so the user is none the wiser... until they try to rmmod their MTD driver while it's being used by UBI/UBIFS!
Regards, Brian
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