Re: [PATCH] of/irq: Add a quirk for controllers with their own definition of interrupt-map
From: Rob Herring <robh@kernel.org>
Date: 2021-11-29 19:17:46
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On Mon, Nov 22, 2021 at 4:30 AM Marc Zyngier [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Since 041284181226 ("of/irq: Allow matching of an interrupt-map local to an interrupt controller"), a handful of interrupt controllers have stopped working correctly. This is due to the DT exposing a non-sensical interrupt-map property, and their drivers relying on the kernel ignoring this property. Since we cannot realistically fix this terrible behaviour, add a quirk for the limited set of devices that have implemented this monster, and document that this is a pretty bad practice. Cc: Rob Herring <robh@kernel.org> Cc: John Crispin <john@phrozen.org> Cc: Biwen Li <redacted> Cc: Chris Brandt <chris.brandt@renesas.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Marc Zyngier <maz@kernel.org> --- drivers/of/irq.c | 37 +++++++++++++++++++++++++++++++++++-- 1 file changed, 35 insertions(+), 2 deletions(-)diff --git a/drivers/of/irq.c b/drivers/of/irq.c index b10f015b2e37..27a5173c813c 100644 --- a/drivers/of/irq.c +++ b/drivers/of/irq.c@@ -76,6 +76,36 @@ struct device_node *of_irq_find_parent(struct device_node *child) } 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). + * + * 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 + * drawing board. + */ +static const char * const of_irq_imap_abusers[] = { + "CBEA,platform-spider-pic", + "sti,platform-spider-pic", + "realtek,rtl-intc", + "fsl,ls1021a-extirq", + "fsl,ls1043a-extirq", + "fsl,ls1088a-extirq", + "renesas,rza1-irqc", +};
I guess this list was obtained by with a: git grep '"interrupt-map"' I suppose that should be sufficient to find all the cases. I'd like to be able to identify this case just from a DT file, but it's not really clear Perhaps a simpler solution to all this is only handle interrupt-map with interrupt-controller if it points to its own node. That works for Apple and I don't see a need beyond that case.
+static bool of_irq_abuses_interrupt_map(struct device_node *np)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(of_irq_imap_abusers); i++)
+ if (of_device_is_compatible(np, of_irq_imap_abusers[i]))
+ return true;
+
+ return false;With a NULL terminated list, you can use of_device_compatible_match() instead . Rob