diff mbox series

[for-4.4,7/7] MIPS: Lantiq: Fix cascaded IRQ setup

Message ID 1491482940-1163-8-git-send-email-amit.pundir@linaro.org
State Superseded
Headers show
Series mips: IRQ stack patches from LEDE | expand

Commit Message

Amit Pundir April 6, 2017, 12:49 p.m. UTC
From: Felix Fietkau <nbd@nbd.name>


With the IRQ stack changes integrated, the XRX200 devices started
emitting a constant stream of kernel messages like this:

[  565.415310] Spurious IRQ: CAUSE=0x1100c300

This is caused by IP0 getting handled by plat_irq_dispatch() rather than
its vectored interrupt handler, which is fixed by commit de856416e714
("MIPS: IRQ Stack: Fix erroneous jal to plat_irq_dispatch").

Fix plat_irq_dispatch() to handle non-vectored IPI interrupts correctly
by setting up IP2-6 as proper chained IRQ handlers and calling do_IRQ
for all MIPS CPU interrupts.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

Acked-by: John Crispin <john@phrozen.org>

Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15077/
[james.hogan@imgtec.com: tweaked commit message]
Signed-off-by: James Hogan <james.hogan@imgtec.com>


(cherry picked from commit 6c356eda225e3ee134ed4176b9ae3a76f793f4dd)
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

---
 arch/mips/lantiq/irq.c | 38 +++++++++++++++++---------------------
 1 file changed, 17 insertions(+), 21 deletions(-)

-- 
2.7.4

Comments

James Hogan April 6, 2017, 1:19 p.m. UTC | #1
Hi Amit,

On Thu, Apr 06, 2017 at 06:19:00PM +0530, Amit Pundir wrote:
> From: Felix Fietkau <nbd@nbd.name>

> 

> With the IRQ stack changes integrated, the XRX200 devices started

> emitting a constant stream of kernel messages like this:

> 

> [  565.415310] Spurious IRQ: CAUSE=0x1100c300

> 

> This is caused by IP0 getting handled by plat_irq_dispatch() rather than

> its vectored interrupt handler, which is fixed by commit de856416e714

> ("MIPS: IRQ Stack: Fix erroneous jal to plat_irq_dispatch").

> 

> Fix plat_irq_dispatch() to handle non-vectored IPI interrupts correctly

> by setting up IP2-6 as proper chained IRQ handlers and calling do_IRQ

> for all MIPS CPU interrupts.

> 

> Signed-off-by: Felix Fietkau <nbd@nbd.name>

> Acked-by: John Crispin <john@phrozen.org>

> Cc: linux-mips@linux-mips.org

> Patchwork: https://patchwork.linux-mips.org/patch/15077/

> [james.hogan@imgtec.com: tweaked commit message]

> Signed-off-by: James Hogan <james.hogan@imgtec.com>

> 

> (cherry picked from commit 6c356eda225e3ee134ed4176b9ae3a76f793f4dd)

> Signed-off-by: Amit Pundir <amit.pundir@linaro.org>


Weren't you going to drop this one?

Cheers
James
Amit Pundir April 6, 2017, 1:25 p.m. UTC | #2
Hi,

On 6 April 2017 at 18:49, James Hogan <james.hogan@imgtec.com> wrote:
> Hi Amit,

>

> On Thu, Apr 06, 2017 at 06:19:00PM +0530, Amit Pundir wrote:

>> From: Felix Fietkau <nbd@nbd.name>

>>

>> With the IRQ stack changes integrated, the XRX200 devices started

>> emitting a constant stream of kernel messages like this:

>>

>> [  565.415310] Spurious IRQ: CAUSE=0x1100c300

>>

>> This is caused by IP0 getting handled by plat_irq_dispatch() rather than

>> its vectored interrupt handler, which is fixed by commit de856416e714

>> ("MIPS: IRQ Stack: Fix erroneous jal to plat_irq_dispatch").

>>

>> Fix plat_irq_dispatch() to handle non-vectored IPI interrupts correctly

>> by setting up IP2-6 as proper chained IRQ handlers and calling do_IRQ

>> for all MIPS CPU interrupts.

>>

>> Signed-off-by: Felix Fietkau <nbd@nbd.name>

>> Acked-by: John Crispin <john@phrozen.org>

>> Cc: linux-mips@linux-mips.org

>> Patchwork: https://patchwork.linux-mips.org/patch/15077/

>> [james.hogan@imgtec.com: tweaked commit message]

>> Signed-off-by: James Hogan <james.hogan@imgtec.com>

>>

>> (cherry picked from commit 6c356eda225e3ee134ed4176b9ae3a76f793f4dd)

>> Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

>

> Weren't you going to drop this one?


I thought you wanted me to drop this one because the
dependent/relevant patches were not pushed to stable at that time. But
I re-read your email and I missed one important part that this
particular patch is valid for a separate bug introduced in IRQ stack
stuff in 4.11. I missed that important part. My apologies for that.
Again.

Greg please drop this one for both 4.4 and 4.9.

Regards,
Amit Pundir

>

> Cheers

> James
diff mbox series

Patch

diff --git a/arch/mips/lantiq/irq.c b/arch/mips/lantiq/irq.c
index 2e7f60c..51cdc46 100644
--- a/arch/mips/lantiq/irq.c
+++ b/arch/mips/lantiq/irq.c
@@ -269,6 +269,11 @@  static void ltq_hw5_irqdispatch(void)
 DEFINE_HWx_IRQDISPATCH(5)
 #endif
 
+static void ltq_hw_irq_handler(struct irq_desc *desc)
+{
+	ltq_hw_irqdispatch(irq_desc_get_irq(desc) - 2);
+}
+
 #ifdef CONFIG_MIPS_MT_SMP
 void __init arch_init_ipiirq(int irq, struct irqaction *action)
 {
@@ -313,23 +318,19 @@  static struct irqaction irq_call = {
 asmlinkage void plat_irq_dispatch(void)
 {
 	unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
-	unsigned int i;
-
-	if ((MIPS_CPU_TIMER_IRQ == 7) && (pending & CAUSEF_IP7)) {
-		do_IRQ(MIPS_CPU_TIMER_IRQ);
-		goto out;
-	} else {
-		for (i = 0; i < MAX_IM; i++) {
-			if (pending & (CAUSEF_IP2 << i)) {
-				ltq_hw_irqdispatch(i);
-				goto out;
-			}
-		}
+	int irq;
+
+	if (!pending) {
+		spurious_interrupt();
+		return;
 	}
-	pr_alert("Spurious IRQ: CAUSE=0x%08x\n", read_c0_status());
 
-out:
-	return;
+	pending >>= CAUSEB_IP;
+	while (pending) {
+		irq = fls(pending) - 1;
+		do_IRQ(MIPS_CPU_IRQ_BASE + irq);
+		pending &= ~BIT(irq);
+	}
 }
 
 static int icu_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
@@ -354,11 +355,6 @@  static const struct irq_domain_ops irq_domain_ops = {
 	.map = icu_map,
 };
 
-static struct irqaction cascade = {
-	.handler = no_action,
-	.name = "cascade",
-};
-
 int __init icu_of_init(struct device_node *node, struct device_node *parent)
 {
 	struct device_node *eiu_node;
@@ -390,7 +386,7 @@  int __init icu_of_init(struct device_node *node, struct device_node *parent)
 	mips_cpu_irq_init();
 
 	for (i = 0; i < MAX_IM; i++)
-		setup_irq(i + 2, &cascade);
+		irq_set_chained_handler(i + 2, ltq_hw_irq_handler);
 
 	if (cpu_has_vint) {
 		pr_info("Setting up vectored interrupts\n");