On 13/08/11 09:54, Emilio G. Cota wrote: > On Fri, Aug 12, 2011 at 12:30:49 +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()'. > (snip) >> +int vme_bridge_get(unsigned int bus_id) > (snip) >> +void vme_bridge_put(struct vme_bridge *bridge) > > Note the input parameter imbalance; in fact this is serious > (see my email on patch 5) because _get() needs to acquire > vme_buses_lock, whereas _put() doesn't. Since a caller with > bridge has bridge->num, but the opposite doesn't hold (num > doesn't give you the bridge without acquiring vme_buses_lock), > it seems reasonable to me to take the bus_id as the input for > both functions, because the requirements on the caller are lower. > Patch 4 makes changes the struct vme_bridge to struct vme_dev. Looking at the callers we are then effectively doing: vme_bridge_get(vme_dev.id) Then in vme_bridge_get(), looping through all the buses to find the one with the correct id... We could just pass in the struct vme_dev to both functions. Martyn > But the locking needs to be handled with care, see my reply > to patch 5. > > Emilio > > _______________________________________________ > devel mailing list > devel@xxxxxxxxxxxxxxxxxxxxxx > http://driverdev.linuxdriverproject.org/mailman/listinfo/devel -- Martyn Welch (Principal Software Engineer) | Registered in England and GE Intelligent Platforms | Wales (3828642) at 100 T +44(0)127322748 | Barbirolli Square, Manchester, E martyn.welch@xxxxxx | M2 3AB VAT:GB 927559189 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
