On Mon, Aug 29, 2011 at 02:40:12PM -0400, Emilio G. Cota wrote: > On Mon, Aug 29, 2011 at 10:51:04 -0700, Greg KH wrote: > > On Mon, Aug 29, 2011 at 11:02:48AM +0200, Manohar Vanga wrote: > > > This patch adds functions that allow for reference counting > > > bridge modules. The patch introduces the functions > > > 'vme_bridge_get()' and 'vme_bridge_put()'. > > > > > > The functions are automatically called during .probe and .remove > > > for drivers. > > > > > > This patch is based on the changes introduced by Emilio G. Cota > > > in the patch: > > > > > > https://lkml.org/lkml/2010/10/25/492 > > > > Generally do not try to couple a module reference count with a device > > count, you are locking code, not data, and we really don't want to lock > > code anymore now that we properly handle device reference counts. > > (snip) > > > > diff --git a/drivers/staging/vme/vme_bridge.h b/drivers/staging/vme/vme_bridge.h > > > index 8959670..ef751a4 100644 > > > --- a/drivers/staging/vme/vme_bridge.h > > > +++ b/drivers/staging/vme/vme_bridge.h > > > @@ -113,6 +113,7 @@ struct vme_bridge { > > > struct device *parent; /* Parent device (eg. pdev->dev for PCI) */ > > > void *driver_priv; /* Private pointer for the bridge driver */ > > > struct list_head bus_list; /* list of VME buses */ > > > + struct module *owner; /* module that owns the bridge */ > > > > Why? When you register the device for this bridge, you should properly > > handle the module reference counting in the vme core for any open sysfs > > files. > > > > Other than that, you shouldn't care about the module reference at all, > > right? > > > > What am I missing here? What is this solving? > > > > confused, > > AFAIK currently a vme bridge driver can be freely removed with rmmod > even if it has devices under it. The patch avoids this by increasing > the refcount of the bridge module every time a device is registered > under it. > > What's the appropriate thing to do when rmmod tries to remove a bridge > module? Let it happen and remove all of the devices under it. That's the way all other bus drivers in the kernel work, why change this type of behavior? thanks, greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
