[tip:irq/urgent] genirq/PM: Restore system wake up from chained interrupts

From: tip-bot for Grygorii Strashko
Date: Tue Nov 10 2015 - 09:16:41 EST

Commit-ID: 4717f133736dec10605da9e29e707144c8d486df
Gitweb: http://git.kernel.org/tip/4717f133736dec10605da9e29e707144c8d486df
Author: Grygorii Strashko <grygorii.strashko@xxxxxx>
AuthorDate: Tue, 10 Nov 2015 11:58:12 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 10 Nov 2015 09:11:31 -0500

genirq/PM: Restore system wake up from chained interrupts

Commit e509bd7da149 ("genirq: Allow migration of chained interrupts
by installing default action") breaks PCS wake up IRQ behaviour on
TI OMAP based platforms (dra7-evm).

TI OMAP IRQ wake up configuration:
|- omap_prcm_register_chain_handler
|- PRCM-irqchip -> PRCM_IO_IRQ
|- pcs_irq_chain_handler
|- pinctrl-irqchip -> PCS_uart1_wakeup_irq

This happens because IRQ PM code (irq/pm.c) is expected to ignore
chained interrupts by default:
static bool suspend_device_irq(struct irq_desc *desc)
if (!desc->action || desc->no_suspend_depth)
return false;
- it's expected !desc->action = true for chained interrupts;

but, after above change, all chained interrupt descriptors will
have default action handler installed - chained_action.
As result, chained interrupts will be silently disabled during system

Hence, fix it by introducing helper function irq_desc_is_chained() and
use it in suspend_device_irq() for chained interrupts identification
and skip them, once detected.

Fixes: e509bd7da149 ("genirq: Allow migration of chained interrupts..")
Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Cc: Tony Lindgren <tony@xxxxxxxxxxx>
Cc: <nsekhar@xxxxxx>
Cc: <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Tony Lindgren <tony@xxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1447149492-20699-1-git-send-email-grygorii.strashko@xxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
kernel/irq/internals.h | 5 +++++
kernel/irq/pm.c | 3 ++-
kernel/irq/proc.c | 2 +-
3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 05c2188..fcab63c 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -199,6 +199,11 @@ static inline int irq_desc_get_node(struct irq_desc *desc)
return irq_common_data_get_node(&desc->irq_common_data);

+static inline int irq_desc_is_chained(struct irq_desc *desc)
+ return (desc->action && desc->action == &chained_action);
bool irq_pm_check_wakeup(struct irq_desc *desc);
void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action);
diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
index 21c6261..84ab239 100644
--- a/kernel/irq/pm.c
+++ b/kernel/irq/pm.c
@@ -70,7 +70,8 @@ void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action)

static bool suspend_device_irq(struct irq_desc *desc)
- if (!desc->action || desc->no_suspend_depth)
+ if (!desc->action || irq_desc_is_chained(desc) ||
+ desc->no_suspend_depth)
return false;

if (irqd_is_wakeup_set(&desc->irq_data)) {
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index a916cf1..a2c02fd 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -475,7 +475,7 @@ int show_interrupts(struct seq_file *p, void *v)
any_count |= kstat_irqs_cpu(i, j);
action = desc->action;
- if ((!action || action == &chained_action) && !any_count)
+ if ((!action || irq_desc_is_chained(desc)) && !any_count)
goto out;

seq_printf(p, "%*d: ", prec, i);
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