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.
M.
--
Jazz is not dead. It just smells funny...
