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Message-Id: <1418660152-17185-2-git-send-email-boris.brezillon@free-electrons.com>
Date: Mon, 15 Dec 2014 17:15:48 +0100
From: Boris Brezillon <boris.brezillon@...e-electrons.com>
To: Thomas Gleixner <tglx@...utronix.de>,
"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Jiri Slaby <jslaby@...e.cz>, linux-serial@...r.kernel.org,
Alessandro Zummo <a.zummo@...ertech.it>,
rtc-linux@...glegroups.com, Mike Turquette <mturquette@...aro.org>,
Nicolas Ferre <nicolas.ferre@...el.com>,
Jean-Christophe Plagniol-Villard <plagnioj@...osoft.com>,
Alexandre Belloni <alexandre.belloni@...e-electrons.com>,
Andrew Victor <linux@...im.org.za>
Cc: linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
Boris Brezillon <boris.brezillon@...e-electrons.com>
Subject: [PATCH 1/5] genirq: Support mixing IRQF_NO_SUSPEND/IRQF_SUSPEND on shared irqs
The current implementation forbid sharing an irq line on devices that do
not request the same behavior on suspend/resume (controlled via the
IRQF_NO_SUSPEND/IRQF_FORCE_RESUME flags).
Add a flag (IRQF_SUSPEND_NOACTION) to specify that you don't want to be
called in suspend mode, and that you already took care of disabling the
interrupt on the device side.
The suspend_device_irq will now move actions specifying the
IRQF_SUSPEND_NOACTION into a temporary list so that they won't be called
when the interrupt is triggered, and resume_irq_actions restores the
suspended actions into the active action list.
Signed-off-by: Boris Brezillon <boris.brezillon@...e-electrons.com>
---
include/linux/interrupt.h | 11 ++++++++
include/linux/irqdesc.h | 3 ++
kernel/irq/pm.c | 71 +++++++++++++++++++++++++++++++++++++++++++++--
3 files changed, 82 insertions(+), 3 deletions(-)
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index d9b05b5..aba3f36 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -57,6 +57,16 @@
* IRQF_NO_THREAD - Interrupt cannot be threaded
* IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device
* resume time.
+ * IRQF_SUSPEND_NOACTION - When sharing an irq, a specific handler can ask to
+ * be disabled when entering suspend. This is
+ * particularly useful on shared irqs where at least
+ * one user is requesting IRQF_NO_SUSPEND while the
+ * others don't want to be active on suspend.
+ * Setting this flag implies taking the appropriate
+ * action to disable device interrupts when entering
+ * suspend, otherwise you might experience spurious
+ * interrupts.
+ *
*/
#define IRQF_DISABLED 0x00000020
#define IRQF_SHARED 0x00000080
@@ -70,6 +80,7 @@
#define IRQF_FORCE_RESUME 0x00008000
#define IRQF_NO_THREAD 0x00010000
#define IRQF_EARLY_RESUME 0x00020000
+#define IRQF_SUSPEND_NOACTION 0x00040000
#define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index faf433a..64a577f 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -22,6 +22,7 @@ struct pt_regs;
* @handle_irq: highlevel irq-events handler
* @preflow_handler: handler called before the flow handler (currently used by sparc)
* @action: the irq action chain
+ * @suspended_action: the irq suspended action chain
* @status: status information
* @core_internal_state__do_not_mess_with_it: core internal status information
* @depth: disable-depth, for nested irq_disable() calls
@@ -54,6 +55,7 @@ struct irq_desc {
irq_preflow_handler_t preflow_handler;
#endif
struct irqaction *action; /* IRQ action list */
+ struct irqaction *suspended_action; /* IRQ suspended action list */
unsigned int status_use_accessors;
unsigned int core_internal_state__do_not_mess_with_it;
unsigned int depth; /* nested irq disables */
@@ -79,6 +81,7 @@ struct irq_desc {
unsigned int nr_actions;
unsigned int no_suspend_depth;
unsigned int force_resume_depth;
+ unsigned int suspend_noaction_depth;
#endif
#ifdef CONFIG_PROC_FS
struct proc_dir_entry *dir;
diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
index 3ca5325..45446e1 100644
--- a/kernel/irq/pm.c
+++ b/kernel/irq/pm.c
@@ -35,17 +35,24 @@ void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action)
{
desc->nr_actions++;
+ if (action->flags & IRQF_SUSPEND_NOACTION) {
+ desc->suspend_noaction_depth++;
+ return;
+ }
+
if (action->flags & IRQF_FORCE_RESUME)
desc->force_resume_depth++;
WARN_ON_ONCE(desc->force_resume_depth &&
- desc->force_resume_depth != desc->nr_actions);
+ (desc->force_resume_depth +
+ desc->suspend_noaction_depth) != desc->nr_actions);
if (action->flags & IRQF_NO_SUSPEND)
desc->no_suspend_depth++;
WARN_ON_ONCE(desc->no_suspend_depth &&
- desc->no_suspend_depth != desc->nr_actions);
+ (desc->no_suspend_depth +
+ desc->suspend_noaction_depth) != desc->nr_actions);
}
/*
@@ -56,6 +63,11 @@ void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action)
{
desc->nr_actions--;
+ if (action->flags & IRQF_SUSPEND_NOACTION) {
+ desc->suspend_noaction_depth--;
+ return;
+ }
+
if (action->flags & IRQF_FORCE_RESUME)
desc->force_resume_depth--;
@@ -63,11 +75,63 @@ void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action)
desc->no_suspend_depth--;
}
+/*
+ * Move all irq actions that specifically set IRQF_SUSPEND_NOACTION
+ * into the suspended action list so that they won't be called if an
+ * interrupt happens.
+ */
+static void suspend_irq_actions(struct irq_desc *desc)
+{
+ struct irqaction *action;
+ struct irqaction *suspended_action = NULL;
+
+ for (action = desc->action; action; action = action->next) {
+ if (!(action->flags & IRQF_SUSPEND_NOACTION))
+ continue;
+
+ if (!suspended_action) {
+ suspended_action = action->next;
+ } else {
+ suspended_action->next = action;
+ suspended_action = action;
+ }
+ }
+
+ BUG_ON(!suspended_action);
+ suspended_action->next = NULL;
+}
+
+/*
+ * Restore all irq actions pushed into the suspended action list.
+ */
+static void resume_irq_actions(struct irq_desc *desc)
+{
+ struct irqaction *action;
+
+ if (!desc->suspended_action)
+ return;
+
+ for (action = desc->action; action && action->next;
+ action = action->next)
+ ;
+
+ BUG_ON(!action);
+ action->next = desc->suspended_action;
+ desc->suspended_action = NULL;
+}
+
static bool suspend_device_irq(struct irq_desc *desc, int irq)
{
- if (!desc->action || desc->no_suspend_depth)
+ if (!desc->action)
return false;
+ if (desc->no_suspend_depth) {
+ if (desc->no_suspend_depth != desc->nr_actions)
+ suspend_irq_actions(desc);
+
+ return false;
+ }
+
if (irqd_is_wakeup_set(&desc->irq_data)) {
irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED);
/*
@@ -131,6 +195,7 @@ EXPORT_SYMBOL_GPL(suspend_device_irqs);
static void resume_irq(struct irq_desc *desc, int irq)
{
irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);
+ resume_irq_actions(desc);
if (desc->istate & IRQS_SUSPENDED)
goto resume;
--
1.9.1
--
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