On Friday 18 August 2006 11:58 am, Alan Stern wrote: > On Fri, 18 Aug 2006, David Brownell wrote: > > > On Friday 18 August 2006 9:28 am, Alan Stern wrote: > > > > > The one interesting aspect is that the dev_set_drvdata calls were > > > moved from the usb_create_hcd and usb_put_hcd routines, where they > > > clearly don't belong, into usb_add_hcd and usb_remove_hcd. This > > > shouldn't cause any problems. > > > > Actually it'd be best to not do that. ... > > Then you're saying that although it won't cause any problems currently, it > would make things difficult in the future or for out-of-tree drivers.
It causes problems for a driver that's currently out-of-tree but which is nearly ready to be circulated ... _and_ is not a good change. > > If they "clearly don't belong", it would be because the driver itself, > > rather than the glue layer, ought to control that driver data field. > > I'll buy that. > > > For example, by pointing to the driver-private structure used to manage > > both roles (host, peripheral), rather than a usbcore structure that's > > irrelevant if usbcore isn't configured (e.g. a peripheral-only board). > > But I don't see that as currently being practical. So meanwhile, > > please leave that part of the setup/create logic as-is. > > The thing is, they _can't_ be left where they are. usb_put_hcd can be > called an arbitrarily large number of times (provided it's balanced by an > equal number of calls to usb_get_hcd) while the driver is still running. > We can't have it setting the driver data to NULL. The only reason it has > worked up until now is that there hasn't been any usb_get_hcd! But the > patch adds one, and it is used in a few places. > > In principle the call in usb_create_hcd could stay where it is. But it > would need to get undone somehow -- where should that happen? Driver data is undefined when no driver is bound; it doesn't actually need to be nulled out... > Maybe it would be best to precede this patch with another one that moves > all those set_drvdata calls into the individual drivers and out of the > core. There's a patch now in Greg's queue which relies on the drvdata to be the HCD (it's the shutdown patch). - Dave ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
