[tip:irq/urgent] genirq: Restore trigger settings in irq_modify_status()

[tip-bot for Marc Zyngier]

Commit-ID:  e8f241893dfbbebe2813c01eac54f263e6a5e59c
Gitweb: http://git.kernel.org/tip/e8f241893dfbbebe2813c01eac54f263e6a5e59c
Author: Marc Zyngier 
AuthorDate: Fri, 18 Aug 2017 10:53:45 +0100
Committer:  Thomas Gleixner 
CommitDate: Fri, 18 Aug 2017 12:04:14 +0200

genirq: Restore trigger settings in irq_modify_status()

irq_modify_status starts by clearing the trigger settings from
irq_data before applying the new settings, but doesn't restore them,
leaving them to IRQ_TYPE_NONE.

That's pretty confusing to the potential request_irq() that could
follow. Instead, snapshot the settings before clearing them, and restore
them if the irq_modify_status() invocation was not changing the trigger.

Fixes: 1e2a7d78499e ("irqdomain: Don't set type when mapping an IRQ")
Reported-and-tested-by: jeffy 
Signed-off-by: Marc Zyngier 
Signed-off-by: Thomas Gleixner 
Cc: Jon Hunter 
Cc: sta...@vger.kernel.org
Link: http://lkml.kernel.org/r/20170818095345.12378-1-marc.zyng...@arm.com

---
 kernel/irq/chip.c | 10 --
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index a3cc37c..3675c60 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -1000,7 +1000,7 @@ EXPORT_SYMBOL_GPL(irq_set_chip_and_handler_name);
 
 void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
 {
-   unsigned long flags;
+   unsigned long flags, trigger, tmp;
struct irq_desc *desc = irq_get_desc_lock(irq, , 0);
 
if (!desc)
@@ -1014,6 +1014,8 @@ void irq_modify_status(unsigned int irq, unsigned long 
clr, unsigned long set)
 
irq_settings_clr_and_set(desc, clr, set);
 
+   trigger = irqd_get_trigger_type(>irq_data);
+
irqd_clear(>irq_data, IRQD_NO_BALANCING | IRQD_PER_CPU |
   IRQD_TRIGGER_MASK | IRQD_LEVEL | IRQD_MOVE_PCNTXT);
if (irq_settings_has_no_balance_set(desc))
@@ -1025,7 +1027,11 @@ void irq_modify_status(unsigned int irq, unsigned long 
clr, unsigned long set)
if (irq_settings_is_level(desc))
irqd_set(>irq_data, IRQD_LEVEL);
 
-   irqd_set(>irq_data, irq_settings_get_trigger_mask(desc));
+   tmp = irq_settings_get_trigger_mask(desc);
+   if (tmp != IRQ_TYPE_NONE)
+   trigger = tmp;
+
+   irqd_set(>irq_data, trigger);
 
irq_put_desc_unlock(desc, flags);
 }

[tip:irq/urgent] genirq: Restore trigger settings in irq_modify_status()

[tip-bot for Marc Zyngier]

Commit-ID:  e8f241893dfbbebe2813c01eac54f263e6a5e59c
Gitweb: http://git.kernel.org/tip/e8f241893dfbbebe2813c01eac54f263e6a5e59c
Author: Marc Zyngier 
AuthorDate: Fri, 18 Aug 2017 10:53:45 +0100
Committer:  Thomas Gleixner 
CommitDate: Fri, 18 Aug 2017 12:04:14 +0200

genirq: Restore trigger settings in irq_modify_status()

irq_modify_status starts by clearing the trigger settings from
irq_data before applying the new settings, but doesn't restore them,
leaving them to IRQ_TYPE_NONE.

That's pretty confusing to the potential request_irq() that could
follow. Instead, snapshot the settings before clearing them, and restore
them if the irq_modify_status() invocation was not changing the trigger.

Fixes: 1e2a7d78499e ("irqdomain: Don't set type when mapping an IRQ")
Reported-and-tested-by: jeffy 
Signed-off-by: Marc Zyngier 
Signed-off-by: Thomas Gleixner 
Cc: Jon Hunter 
Cc: sta...@vger.kernel.org
Link: http://lkml.kernel.org/r/20170818095345.12378-1-marc.zyng...@arm.com

---
 kernel/irq/chip.c | 10 --
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index a3cc37c..3675c60 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -1000,7 +1000,7 @@ EXPORT_SYMBOL_GPL(irq_set_chip_and_handler_name);
 
 void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
 {
-   unsigned long flags;
+   unsigned long flags, trigger, tmp;
struct irq_desc *desc = irq_get_desc_lock(irq, , 0);
 
if (!desc)
@@ -1014,6 +1014,8 @@ void irq_modify_status(unsigned int irq, unsigned long 
clr, unsigned long set)
 
irq_settings_clr_and_set(desc, clr, set);
 
+   trigger = irqd_get_trigger_type(>irq_data);
+
irqd_clear(>irq_data, IRQD_NO_BALANCING | IRQD_PER_CPU |
   IRQD_TRIGGER_MASK | IRQD_LEVEL | IRQD_MOVE_PCNTXT);
if (irq_settings_has_no_balance_set(desc))
@@ -1025,7 +1027,11 @@ void irq_modify_status(unsigned int irq, unsigned long 
clr, unsigned long set)
if (irq_settings_is_level(desc))
irqd_set(>irq_data, IRQD_LEVEL);
 
-   irqd_set(>irq_data, irq_settings_get_trigger_mask(desc));
+   tmp = irq_settings_get_trigger_mask(desc);
+   if (tmp != IRQ_TYPE_NONE)
+   trigger = tmp;
+
+   irqd_set(>irq_data, trigger);
 
irq_put_desc_unlock(desc, flags);
 }