On Wed, Nov 27, 2013 at 03:56:29PM +0000, Grant Likely wrote: > On Mon, 25 Nov 2013 10:49:55 +0100, Thierry Reding <thierry.reding@xxxxxxxxx> wrote: > > On Mon, Nov 25, 2013 at 10:25:50AM +0100, Thierry Reding wrote: > > > On Sun, Nov 24, 2013 at 09:36:51PM +0000, Grant Likely wrote: > > > > On Fri, 22 Nov 2013 16:43:35 -0800, Tony Lindgren <tony@xxxxxxxxxxx> wrote: > > > > > Currently we get the following kind of errors if we try to use > > > > > interrupt phandles to irqchips that have not yet initialized: > > > > > > > > > > irq: no irq domain found for /ocp/pinmux@48002030 ! > > > > > WARNING: CPU: 0 PID: 1 at drivers/of/platform.c:171 of_device_alloc+0x144/0x184() > > > > > Modules linked in: > > > > > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.12.0-00038-g42a9708 #1012 > > > > > (show_stack+0x14/0x1c) > > > > > (dump_stack+0x6c/0xa0) > > > > > (warn_slowpath_common+0x64/0x84) > > > > > (warn_slowpath_null+0x1c/0x24) > > > > > (of_device_alloc+0x144/0x184) > > > > > (of_platform_device_create_pdata+0x44/0x9c) > > > > > (of_platform_bus_create+0xd0/0x170) > > > > > (of_platform_bus_create+0x12c/0x170) > > > > > (of_platform_populate+0x60/0x98) > > > > > ... > > > > > > > > > > This is because we're wrongly trying to populate resources that are not > > > > > yet available. It's perfectly valid to create irqchips dynamically, > > > > > so let's fix up the issue by populating the interrupt resources based > > > > > on a notifier call instead. > > > > > > > > > > Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> > > > > > > > > > > --- > > > > > > > > > > Rob & Grant, care to merge this for the -rc if this looks OK to you? > > > > > > > > > > These happen for example when using interrupts-extended for omap > > > > > wake-up interrupts where the irq domain is created by pinctrl-single.c > > > > > at module_init time. > > > > > > > > > > --- a/drivers/of/platform.c > > > > > +++ b/drivers/of/platform.c > > > > > @@ -130,6 +130,56 @@ void of_device_make_bus_id(struct device *dev) > > > > > dev_set_name(dev, "%s.%d", node->name, magic - 1); > > > > > } > > > > > > > > > > +/* > > > > > + * The device interrupts are not necessarily available for all > > > > > + * irqdomains initially so we need to populate them using a > > > > > + * notifier. > > > > > + */ > > > > > +static int of_device_resource_notify(struct notifier_block *nb, > > > > > + unsigned long event, void *dev) > > > > > +{ > > > > > + struct platform_device *pdev = to_platform_device(dev); > > > > > + struct device_node *np = pdev->dev.of_node; > > > > > + struct resource *res = pdev->resource; > > > > > + struct resource *irqr = NULL; > > > > > + int num_irq, i, found = 0; > > > > > + > > > > > + if (event != BUS_NOTIFY_BIND_DRIVER) > > > > > + return 0; > > > > > + > > > > > + if (!np) > > > > > + goto out; > > > > > + > > > > > + num_irq = of_irq_count(np); > > > > > + if (!num_irq) > > > > > + goto out; > > > > > + > > > > > + for (i = 0; i < pdev->num_resources; i++, res++) { > > > > > + if (res->flags != IORESOURCE_IRQ || > > > > > + res->start != -EPROBE_DEFER || > > > > > + res->end != -EPROBE_DEFER) > > > > > + continue; > > > > > + > > > > > + if (!irqr) > > > > > + irqr = res; > > > > > + found++; > > > > > + } > > > > > + > > > > > + if (!found) > > > > > + goto out; > > > > > + > > > > > + if (found != num_irq) { > > > > > + dev_WARN(dev, "error populating irq resources: %i != %i\n", > > > > > + found, num_irq); > > > > > + goto out; > > > > > + } > > > > > + > > > > > + WARN_ON(of_irq_to_resource_table(np, irqr, num_irq) != num_irq); > > > > > + > > > > > +out: > > > > > + return NOTIFY_DONE; > > > > > +} > > > > > + > > > > > /** > > > > > * of_device_alloc - Allocate and initialize an of_device > > > > > * @np: device node to assign to device > > > > > @@ -168,7 +218,13 @@ struct platform_device *of_device_alloc(struct device_node *np, > > > > > rc = of_address_to_resource(np, i, res); > > > > > WARN_ON(rc); > > > > > } > > > > > - WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq); > > > > > + > > > > > + /* See of_device_resource_notify for populating interrupts */ > > > > > + for (i = 0; i < num_irq; i++, res++) { > > > > > + res->flags = IORESOURCE_IRQ; > > > > > + res->start = -EPROBE_DEFER; > > > > > + res->end = -EPROBE_DEFER; > > > > > + } > > > > > > > > I actually like the idea of completely allocating the resource structure > > > > but leaving some entries empty. However, I agree with rmk that putting > > > > garbage into a resource structure is a bad idea. What about changing the > > > > value of flags to 0 or some other value to be obviously an empty > > > > property and give the follow up parsing some context about which ones it > > > > needs to attempt to recalculate? > > > > > > When I worked on this a while back I came to the same conclusion. It's > > > nice to allocate all the resources at once, because the number of them > > > doesn't change, only their actually values. > > > > I should maybe add: one issue that was raised during review of my > > initial patch series was that we'll also need to cope with situations > > like the following: > > > > 1) device's interrupt parent is probed (assigned IRQ base X) > > 2) device is probed (interrupt parent there, therefore gets > > assigned IRQ (X + z) > > 3) device in removed > > 4) device's interrupt parent is removed > > 5) device is probed (deferred because interrupt parent isn't > > there) > > 6) device's interrupt parent is probed (assigned IRQ base Y) > > 7) device is probed, gets assigned IRQ (Y + z) > > > > So not only do we have to track which resources are interrupt resources, > > but we also need to have them reassigned everytime the device is probed, > > therefore interrupt mappings need to be properly disposed and the values > > invalidated when probing is deferred or the device removed. > > Yes, that is a problem, but the only way to handle that is to always > recalcuate all resource references at probe time. I don't feel good > about handling that in the core. I'd rather move drivers away from > referencing the resources table directly and instead use an API. Then > the resources table could be missing entirely. Are you suggesting something like this? --- diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 3a94b799f166..c894d1af3a5e 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -13,6 +13,7 @@ #include <linux/string.h> #include <linux/platform_device.h> #include <linux/of_device.h> +#include <linux/of_irq.h> #include <linux/module.h> #include <linux/init.h> #include <linux/dma-mapping.h> @@ -87,7 +88,12 @@ int platform_get_irq(struct platform_device *dev, unsigned int num) return -ENXIO; return dev->archdata.irqs[num]; #else - struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num); + struct resource *r; + + if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) + return irq_of_parse_and_map(dev->dev.of_node, num); + + r = platform_get_resource(dev, IORESOURCE_IRQ, num); return r ? r->start : -ENXIO; #endif
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