Some (admittedly odd) irqchips perform functions that are not directly
related to any of their child IRQ lines, and therefore need to perform
some tasks during suspend/resume regardless of whether there are
any "installed" interrupts for the irqchip. However, the current
generic-chip framework does not call the chip's irq_{suspend,resume}
when there are no interrupts installed (this makes sense, because there
are no irq_data objects for such a call to be made).
More specifically, irq-bcm7120-l2 configures both a forwarding mask
(which affects other top-level GIC IRQs) and a second-level interrupt
mask (for managing its own child interrupts). The former must be
saved/restored on suspend/resume, even when there's nothing to do for
the latter.
This patch adds a second set of suspend/resume hooks to irq_chip, this
time to represent *chip* suspend/resume, rather than IRQ suspend/resume.
These callbacks will always be called for an irqchip and are based on
the per-chip irq_chip_generic struct, rather than the per-IRQ irq_data
struct.
The original problem report is described in extra detail here:
http://lkml.kernel.org/g/20150619224123.GL4917@ld-irv-0074
Signed-off-by: Brian Norris <computersforpeace@xxxxxxxxx>
---
include/linux/irq.h | 10 ++++++++++
kernel/irq/generic-chip.c | 6 ++++++
2 files changed, 16 insertions(+)
diff --git a/include/linux/irq.h b/include/linux/irq.h
index de3213d271ff..2a672d2434a5 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -293,6 +293,8 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
return d->hwirq;
}
+struct irq_chip_generic;
+
/**
* struct irq_chip - hardware interrupt chip descriptor
*
@@ -317,6 +319,12 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
* @irq_suspend: function called from core code on suspend once per chip
* @irq_resume: function called from core code on resume once per chip
* @irq_pm_shutdown: function called from core code on shutdown once per chip
+ * @chip_suspend: function called from core code on suspend once per
+ * chip; for handling chip details even when no interrupts
+ * are in use
+ * @chip_resume: function called from core code on resume once per chip;
+ * for handling chip details even when no interrupts are
+ * in use
* @irq_calc_mask: Optional function to set irq_data.mask for special cases
* @irq_print_chip: optional to print special chip info in show_interrupts
* @irq_request_resources: optional to request resources before calling
@@ -357,6 +365,8 @@ struct irq_chip {
void (*irq_suspend)(struct irq_data *data);
void (*irq_resume)(struct irq_data *data);
void (*irq_pm_shutdown)(struct irq_data *data);
+ void (*chip_suspend)(struct irq_chip_generic *gc);
+ void (*chip_resume)(struct irq_chip_generic *gc);
void (*irq_calc_mask)(struct irq_data *data);
diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c
index 15b370daf234..fe25e72d5d13 100644
--- a/kernel/irq/generic-chip.c
+++ b/kernel/irq/generic-chip.c
@@ -553,6 +553,9 @@ static int irq_gc_suspend(void)
if (data)
ct->chip.irq_suspend(data);
}
+
+ if (ct->chip.chip_suspend)
+ ct->chip.chip_suspend(gc);
}
return 0;
}
@@ -564,6 +567,9 @@ static void irq_gc_resume(void)
list_for_each_entry(gc, &gc_list, list) {
struct irq_chip_type *ct = gc->chip_types;
+ if (ct->chip.chip_resume)
+ ct->chip.chip_resume(gc);
+
if (ct->chip.irq_resume) {
struct irq_data *data = irq_gc_get_irq_data(gc);
--
1.9.1
