On Thu, Apr 16, 2015 at 5:40 AM, Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> wrote: > On 04/15/2015 10:35 AM, Rob Herring wrote: >> On Wed, Apr 15, 2015 at 9:17 AM, Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> wrote: > >>> 2. Should DT-specific drivers not be using irq_of_parse_and_map()? >>> On probe failure irq_dispose_mapping() will be junking the mapping, >>> thus invalidating the irq assignment in the platform resource table, >>> which breaks platform drivers which might otherwise probe successfully. >> >> Generally no, they should not use irq_of_parse_and_map as we want >> drivers to work with platform_data, DT, ACPI, or Bob's Firmware >> Interface. I think most users are PPC drivers which don't have so much >> of the probe ordering problems. > > Apologies for hijacking this thread for a moment. > > If of_device_alloc() creates the irq mapping, and no driver probes succeed, > what is disposing the mapping? > > Similarly, if a platform driver fails its probe after platform_get_irq() > what should dispose of that mapping? The mapping is created by the irqchip init, not of_device_alloc or platform_get_irq. Disposing would occur when the irqchip is hot unplugged. Perhaps we could save some memory by also creating the irqdesc when we probe. Of course, the resources set by of_device_alloc would be stale if unplug happened, but platform_get_irq would be okay. However, I think we don't reference count irqchips to prevent their hot unplug while in use. GPIOs have similar hotplug issues and that is being worked on. Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
