On Wed, Jan 22, 2020 at 03:49:39PM +0100, Greg Kroah-Hartman wrote: > On Wed, Jan 22, 2020 at 04:40:48PM +0200, Mika Westerberg wrote: > > On Wed, Jan 22, 2020 at 02:43:59PM +0100, Greg Kroah-Hartman wrote: > > > > + if (!scu->dev) > > > > + goto err_unlock; > > > > + if (!try_module_get(scu->dev->driver->owner)) > > > > + goto err_unlock; > > > > + mutex_unlock(&ipclock); > > > > + return scu; > > > > > > NO REFERENCE COUNT INCREMENT??? > > > > You mean increment the scu->dev reference count? I kind of thought that > > the try_module_get() should make sure the thing stays there as long as > > the caller has not called _put() but now when I think about it bit more > > we would need to do device_get() here as well. > > module reference counts handle _code_ while structure reference counts > handle _data_. > > You should almost never need to worry about module reference counts if > your code is structured properly, only handle the reference counts on > the pointers you throw around. > > The fact that you are even calling try_module_get() is a huge flag that > something is wrong here. Thanks for the explanation! I'll keep this in mind and make sure the next version has reference counting done accordingly.
