Hi Marc, Thank you for the review. On Thu, Dec 9, 2021 at 8:07 AM Marc Zyngier <maz@xxxxxxxxxx> wrote: > > On 2021-12-09 00:10, Lad Prabhakar wrote: > > of_device_alloc() in early boot stage creates a interrupt mapping if > > there exists a "interrupts" property in the node. > > > > For hierarchical interrupt domains using "interrupts" property in the > > node > > bypassed the hierarchical setup and messed up the irq setup. > > > > This patch adds a check in of_device_alloc() to skip interrupt mapping > > if > > "not-interrupt-producer" property is present in the node. This allows > > nodes to describe the interrupts using "interrupts" property. > > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> > > --- > > Hi All, > > > > Spawning from discussion [1], here is simple patch (not the ideal > > probably > > welcome for suggestions) from stopping the OF code from creating a map > > for > > the interrupts when using "interrupts" property. > > > > [1] https://lore.kernel.org/lkml/87pmqrck2m.wl-maz@xxxxxxxxxx/ > > T/#mbd1e47c1981082aded4b32a52e2c04291e515508 > > > > Cheers, > > Prabhakar > > --- > > drivers/of/platform.c | 13 ++++++++++--- > > 1 file changed, 10 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/of/platform.c b/drivers/of/platform.c > > index b3faf89744aa..629776ca1721 100644 > > --- a/drivers/of/platform.c > > +++ b/drivers/of/platform.c > > @@ -114,7 +114,7 @@ struct platform_device *of_device_alloc(struct > > device_node *np, > > struct device *parent) > > { > > struct platform_device *dev; > > - int rc, i, num_reg = 0, num_irq; > > + int rc, i, num_reg = 0, num_irq = 0; > > struct resource *res, temp_res; > > > > dev = platform_device_alloc("", PLATFORM_DEVID_NONE); > > @@ -124,7 +124,14 @@ struct platform_device *of_device_alloc(struct > > device_node *np, > > /* count the io and irq resources */ > > while (of_address_to_resource(np, num_reg, &temp_res) == 0) > > num_reg++; > > - num_irq = of_irq_count(np); > > + > > + /* > > + * we don't want to map the interrupts of hierarchical interrupt > > domain > > + * into the parent domain yet. This will be the job of the > > hierarchical > > + * interrupt driver code to map the interrupts as and when needed. > > + */ > > + if (!of_property_read_bool(np, "not-interrupt-producer")) > > I don't think this is right. If anything, the expected behaviour should > be > indicated by the driver and not the device node. > > > + num_irq = of_irq_count(np); > > > > /* Populate the resource table */ > > if (num_irq || num_reg) { > > @@ -140,7 +147,7 @@ struct platform_device *of_device_alloc(struct > > device_node *np, > > rc = of_address_to_resource(np, i, res); > > WARN_ON(rc); > > } > > - if (of_irq_to_resource_table(np, res, num_irq) != num_irq) > > + if (num_irq && of_irq_to_resource_table(np, res, num_irq) != > > num_irq) > > pr_debug("not all legacy IRQ resources mapped for %pOFn\n", > > np); > > } > > The root of the issue is that all the resource allocation is done > upfront, > way before we even have a driver that could potentially deal with this > device. This is a potential waste of resource, and it triggers the > issue you noticed. > > If you delay the resource allocation until there is an actual match with > a > driver, you could have a per-driver flag telling you whether the IRQ > allocation should be performed before the probe() function is called. > As suggested by Rob, if we switch the drivers to use platform_get_resource(pdev, IORESOURCE_IRQ, n) call with platform_get_irq() this code should go away and with this switch the resource allocation will happen demand. Is this approach OK? Cheers, Prabhakar > M. > -- > Jazz is not dead. It just smells funny...
