This is a note to let you know that I've just added the patch titled
irqchip/realtek-rtl: Fix off-by-one in routing
to the 5.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
irqchip-realtek-rtl-fix-off-by-one-in-routing.patch
and it can be found in the queue-5.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7cfcfd7b1f77d6f3dc263e80021b7080a3aa7fde
Author: Sander Vanheule <sander@xxxxxxxxxxxxx>
Date: Sun Jan 9 15:54:33 2022 +0100
irqchip/realtek-rtl: Fix off-by-one in routing
[ Upstream commit 91351b5dd0fd494eb2d85e1bb6aca77b067447e0 ]
There is an offset between routing values (1..6) and the connected MIPS
CPU interrupts (2..7), but no distinction was made between these two
values.
This issue was previously hidden during testing, because an interrupt
mapping was used where for each required interrupt another (unused)
routing was configured, with an offset of +1.
Offset the CPU IRQ numbers by -1 to retrieve the correct routing value.
Fixes: 9f3a0f34b84a ("irqchip: Add support for Realtek RTL838x/RTL839x interrupt controller")
Signed-off-by: Sander Vanheule <sander@xxxxxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/177b920aa8d8610615692d0e657e509f363c85ca.1641739718.git.sander@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/irqchip/irq-realtek-rtl.c b/drivers/irqchip/irq-realtek-rtl.c
index d6788dd93c7bb..568614edd88f4 100644
--- a/drivers/irqchip/irq-realtek-rtl.c
+++ b/drivers/irqchip/irq-realtek-rtl.c
@@ -95,7 +95,8 @@ static void realtek_irq_dispatch(struct irq_desc *desc)
* SoC interrupts are cascaded to MIPS CPU interrupts according to the
* interrupt-map in the device tree. Each SoC interrupt gets 4 bits for
* the CPU interrupt in an Interrupt Routing Register. Max 32 SoC interrupts
- * thus go into 4 IRRs.
+ * thus go into 4 IRRs. A routing value of '0' means the interrupt is left
+ * disconnected. Routing values {1..15} connect to output lines {0..14}.
*/
static int __init map_interrupts(struct device_node *node, struct irq_domain *domain)
{
@@ -134,7 +135,7 @@ static int __init map_interrupts(struct device_node *node, struct irq_domain *do
of_node_put(cpu_ictl);
cpu_int = be32_to_cpup(imap + 2);
- if (cpu_int > 7)
+ if (cpu_int > 7 || cpu_int < 2)
return -EINVAL;
if (!(mips_irqs_set & BIT(cpu_int))) {
@@ -143,7 +144,8 @@ static int __init map_interrupts(struct device_node *node, struct irq_domain *do
mips_irqs_set |= BIT(cpu_int);
}
- regs[(soc_int * 4) / 32] |= cpu_int << (soc_int * 4) % 32;
+ /* Use routing values (1..6) for CPU interrupts (2..7) */
+ regs[(soc_int * 4) / 32] |= (cpu_int - 1) << (soc_int * 4) % 32;
imap += 3;
}
