On Wed, 16 Sep 2015, Marc Zyngier wrote: > On 16/09/15 02:53, Rafael J. Wysocki wrote: > > I've just seen quite a few bugs where a pointer to something completely invalid > > have been silently passed via (void *) which often results in very interesting > > breakage (that is really hard to debug for that matter). > > I actually tried to prototype this yesterday, and ended up in hell. The > main issue is the point where the generic irqdomain code meets the DT > subsystem (which is basically any interrupt controller, including those > being ACPI driven). The domain_token to of_node path is dead easy, but > you cannot do the reverse conversion, so this would have to spread > around like a cancer. I gave up. > > At this stage, I see two options: sticking with (void *) with the risk > of breakage and subtle bugs which we all love to track down (not!), or > do a major U-turn and make device_node a strict requirement for domain > lookup. > > After the above experiment, I now see some value in actually keeping > device_node around, using it as the token, and allocating it when > required (the typical case being those interrupt controllers that are > both DT and ACPI). I'll play with it a bit more. Right. We already have the fwnode_type in struct device_node, so we can reuse it. If you care about the size of the struct, then you can make some of the struct members conditional on CONFIG_OF. Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
