[PATCH net-next 2/6] net: ipa: distinguish system from runtime suspend

From: Alex Elder
Date: Thu Aug 12 2021 - 15:50:53 EST


Add a new flag that is set when the hardware is suspended due to a
system suspend operation, distingishing it from runtime suspend.
Use it in the SUSPEND IPA interrupt handler to determine whether to
trigger a system resume because of the event. Define new suspend
and resume power management callback functions to set and clear the
new flag, respectively.

Signed-off-by: Alex Elder <elder@xxxxxxxxxx>
---
drivers/net/ipa/ipa_clock.c | 38 ++++++++++++++++++++++++++++++-------
1 file changed, 31 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ipa/ipa_clock.c b/drivers/net/ipa/ipa_clock.c
index cdbaba6618e9e..8f25107c1f1e7 100644
--- a/drivers/net/ipa/ipa_clock.c
+++ b/drivers/net/ipa/ipa_clock.c
@@ -47,10 +47,12 @@ struct ipa_interconnect {
/**
* enum ipa_power_flag - IPA power flags
* @IPA_POWER_FLAG_RESUMED: Whether resume from suspend has been signaled
+ * @IPA_POWER_FLAG_SYSTEM: Hardware is system (not runtime) suspended
* @IPA_POWER_FLAG_COUNT: Number of defined power flags
*/
enum ipa_power_flag {
IPA_POWER_FLAG_RESUMED,
+ IPA_POWER_FLAG_SYSTEM,
IPA_POWER_FLAG_COUNT, /* Last; not a flag */
};

@@ -281,6 +283,27 @@ int ipa_clock_put(struct ipa *ipa)
return pm_runtime_put(&ipa->pdev->dev);
}

+static int ipa_suspend(struct device *dev)
+{
+ struct ipa *ipa = dev_get_drvdata(dev);
+
+ __set_bit(IPA_POWER_FLAG_SYSTEM, ipa->clock->flags);
+
+ return pm_runtime_force_suspend(dev);
+}
+
+static int ipa_resume(struct device *dev)
+{
+ struct ipa *ipa = dev_get_drvdata(dev);
+ int ret;
+
+ ret = pm_runtime_force_resume(dev);
+
+ __clear_bit(IPA_POWER_FLAG_SYSTEM, ipa->clock->flags);
+
+ return ret;
+}
+
/* Return the current IPA core clock rate */
u32 ipa_clock_rate(struct ipa *ipa)
{
@@ -299,12 +322,13 @@ u32 ipa_clock_rate(struct ipa *ipa)
*/
static void ipa_suspend_handler(struct ipa *ipa, enum ipa_irq_id irq_id)
{
- /* Just report the event, and let system resume handle the rest.
- * More than one endpoint could signal this; if so, ignore
- * all but the first.
+ /* To handle an IPA interrupt we will have resumed the hardware
+ * just to handle the interrupt, so we're done. If we are in a
+ * system suspend, trigger a system resume.
*/
- if (!test_and_set_bit(IPA_POWER_FLAG_RESUMED, ipa->clock->flags))
- pm_wakeup_dev_event(&ipa->pdev->dev, 0, true);
+ if (!__test_and_set_bit(IPA_POWER_FLAG_RESUMED, ipa->clock->flags))
+ if (test_bit(IPA_POWER_FLAG_SYSTEM, ipa->clock->flags))
+ pm_wakeup_dev_event(&ipa->pdev->dev, 0, true);

/* Acknowledge/clear the suspend interrupt on all endpoints */
ipa_interrupt_suspend_clear_all(ipa->interrupt);
@@ -390,8 +414,8 @@ void ipa_clock_exit(struct ipa_clock *clock)
}

const struct dev_pm_ops ipa_pm_ops = {
- .suspend = pm_runtime_force_suspend,
- .resume = pm_runtime_force_resume,
+ .suspend = ipa_suspend,
+ .resume = ipa_resume,
.runtime_suspend = ipa_runtime_suspend,
.runtime_resume = ipa_runtime_resume,
.runtime_idle = ipa_runtime_idle,
--
2.27.0