On Tue, 02 Jul 2024 21:48:23 +0100,
Rob Herring [off-list ref] wrote:

On Tue, Jul 2, 2024 at 10:54 AM Marc Zyngier [off-list ref] wrote:

quoted

On Sun, 30 Jun 2024 11:21:55 +0100,
Christian Zigotzky [off-list ref] wrote:

quoted

Hello,

There is an issue with the identification of ATA drives with our
P.A. Semi Nemo boards [1] after the
commit "of/irq: Factor out parsing of interrupt-map parent
phandle+args from of_irq_parse_raw()" [2].

[snip]

My earlier request for valuable debug information still stands. But
while you're at it, can you please give the following hack a go?

        M.

--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c

@@ -282,8 +282,10 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)

                        oldimap = imap;
                        imap = of_irq_parse_imap_parent(oldimap, imaplen, out_irq);
-                       if (!imap)
-                               goto fail;
+                       if (!imap) {
+                               match = 0;
+                               break;
+                       }

AFAICT reading the DT, I don't think this would fix it. imap should
only be null if malformed. This case to me looks like interrupt-map
has the correct cell sizes, but just never matches to do the mapping.
So maybe imaplen is off and that causes us to end up here, but if
there's an error I don't see it. A boot with DEBUG enabled in
drivers/of/irq.c would help.

quoted

                        match &= of_device_is_available(out_irq->np);
                        if (match)

This may not be the final workaround even if it solves your boot
problem, but will at least give us a hint at what is going wrong.

I have the fuzzy feeling that we may be able to lob this broken system
as part of the of_irq_imap_abusers[] array, which would solve things
pretty "neatly".

I think this would work and would consolidate the work-arounds. It
would need either "pasemi,rootbus" or "pa-pxp" added to the list.

I'd be all for this.

	M.

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 462375b293e47..c94203ce65bb3 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c

@@ -81,7 +81,8 @@ EXPORT_SYMBOL_GPL(of_irq_find_parent);
 /*
  * These interrupt controllers abuse interrupt-map for unspeakable
  * reasons and rely on the core code to *ignore* it (the drivers do
- * their own parsing of the property).
+ * their own parsing of the property). The PAsemi entry covers a
+ * non-sensical interrupt-map that is better left ignored.
  *
  * If you think of adding to the list for something *new*, think
  * again. There is a high chance that you will be sent back to the

@@ -95,6 +96,7 @@ static const char * const of_irq_imap_abusers[] = {
 	"fsl,ls1043a-extirq",
 	"fsl,ls1088a-extirq",
 	"renesas,rza1-irqc",
+	"pasemi,rootbus",
 	NULL,
 };
 

@@ -293,20 +295,8 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
 			imaplen -= imap - oldimap;
 			pr_debug(" -> imaplen=%d\n", imaplen);
 		}
-		if (!match) {
-			if (intc) {
-				/*
-				 * The PASEMI Nemo is a known offender, so
-				 * let's only warn for anyone else.
-				 */
-				WARN(!IS_ENABLED(CONFIG_PPC_PASEMI),
-				     "%pOF interrupt-map failed, using interrupt-controller\n",
-				     ipar);
-				return 0;
-			}
-
+		if (!match)
 			goto fail;
-		}
 
 		/*
 		 * Successfully parsed an interrupt-map translation; copy new

-- 
Without deviation from the norm, progress is not possible.