[4.4-rc][PATCH] genirq / PM: restore system wake up from chained interrupts

2015-11-10 Thread Grygorii Strashko
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:
GIC-irqchip->PCM_IRQ
  |- 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
suspend.

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.

Cc: Mika Westerberg 
Cc: Tony Lindgren 
Fixes: e509bd7da149 ("genirq: Allow migration of chained interrupts..")
Signed-off-by: Grygorii Strashko 
---
 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(>irq_common_data);
 }
 
+static inline int irq_desc_is_chained(struct irq_desc *desc)
+{
+   return (desc->action && desc->action == _action);
+}
+
 #ifdef CONFIG_PM_SLEEP
 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 e80c440..cea1de0 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(>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)
for_each_online_cpu(j)
any_count |= kstat_irqs_cpu(i, j);
action = desc->action;
-   if ((!action || action == _action) && !any_count)
+   if ((!action || irq_desc_is_chained(desc)) && !any_count)
goto out;
 
seq_printf(p, "%*d: ", prec, i);
-- 
2.6.2

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Re: [4.4-rc][PATCH] genirq / PM: restore system wake up from chained interrupts

2015-11-10 Thread Mika Westerberg
On Tue, Nov 10, 2015 at 11:58:12AM +0200, Grygorii Strashko wrote:
> 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:
> GIC-irqchip->PCM_IRQ
>   |- 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;

Indeed it is. I missed that, sorry.

> 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
> suspend.
> 
> 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.
> 
> Cc: Mika Westerberg 

FWIW,

Reviewed-by: Mika Westerberg 
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