On Tue, Nov 19, 2013 at 5:22 PM, Grygorii Strashko <grygorii.strashko@xxxxxx> wrote: > On 11/19/2013 01:06 AM, Linus Walleij wrote: >> The problem that appear is if someone is using platform data-provided >> IRQs off the irq_chip without calling gpio_to_irq() on the GPIO line >> first. This has been determined to be legal to do, so preferably >> create the map when registering the lines. > > Ok, I understand. It may fail in case if someone will define/calculate > IRQ number for device manually in board code, like: > dev_irq = (DA850_N_CP_INTC_IRQ + gpioN) Usually people just hardcode the IRQ value or use some #define, like they have often also done with GPIO numbers ... > Also, looks like It is possible to fail if Main/arch IRQ controller > code doesn't make call of irq_alloc_descs() during init, so > allocated_irqs will be empty. If you use irq_domain_add_simple() the irqdomain core will actually attempt to do this. But if you use a linear domain, you have to create these irqdescs as you go. The simplest way to do this is to call irq_create_mapping() on all IRQs, because that call will also allocate some descriptor. > Before recommending that, I've checked Davinci platform code and didn't > find any risk places - BUT, Seems my findings need to be confirmed by > Sekhar. It's no big deal, but I just want you to be aware that this may cause a problem at some point. >> I think you should try to keep the 5 irqdomains, but whatever >> gives the simplest code is usually the right answer, and >> divide-and-conquer (split down the problem) is usually a good >> idea. >> >> How the GPIO block(s) are represented in the device tree is >> another totally separate issue about hardware description, >> do not let the device tree model your driver structure. > > > Thanks for you comments, but looks like I have to be more specific :) > > How irq_find_host() will look for proper IRQ domain in our case? > And will it work at all, taking into account that all (5) IRQ domains > will have the same value of "of_node" property? > of_irq_to_resource() > |-irq_of_parse_and_map() > |-irq_create_of_mapping() > |-irq_find_host(irq_data->np) > where np will point on GPIO node. > > As result my question is about what do DT core frameworks allow or not > allow to do? And according to that implementation of driver can be > changed. Hm, I'm not like a super-expert on the interrupt core, but maybe you need to create subnodes inside the top node to represent this, then use of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev); to populate them from the main node. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
