diff mbox series

[v3,4/5] irqchip: qcom-pdc: Introduce irq_set_wake call

Message ID 1592818308-23001-5-git-send-email-mkshah@codeaurora.org
State New
Headers show
Series [v3,1/5] pinctrl: qcom: Remove irq_disable callback from msmgpio irqchip | expand

Commit Message

Maulik Shah June 22, 2020, 9:31 a.m. UTC
Remove irq_disable callback to allow lazy disable for pdc interrupts.

Add irq_set_wake callback that unmask interrupt in HW when drivers
mark interrupt for wakeup. Interrupt will be cleared in HW during
lazy disable if its not marked for wakeup.

Signed-off-by: Maulik Shah <mkshah@codeaurora.org>
---
 drivers/irqchip/qcom-pdc.c | 34 ++++++++++++++++------------------
 1 file changed, 16 insertions(+), 18 deletions(-)

Comments

Doug Anderson July 13, 2020, 10:16 p.m. UTC | #1
Hi,

On Mon, Jun 22, 2020 at 2:33 AM Maulik Shah <mkshah@codeaurora.org> wrote:
>

> Remove irq_disable callback to allow lazy disable for pdc interrupts.

>

> Add irq_set_wake callback that unmask interrupt in HW when drivers

> mark interrupt for wakeup. Interrupt will be cleared in HW during

> lazy disable if its not marked for wakeup.

>

> Signed-off-by: Maulik Shah <mkshah@codeaurora.org>

> ---

>  drivers/irqchip/qcom-pdc.c | 34 ++++++++++++++++------------------

>  1 file changed, 16 insertions(+), 18 deletions(-)

>

> diff --git a/drivers/irqchip/qcom-pdc.c b/drivers/irqchip/qcom-pdc.c

> index 6ae9e1f..8beb6f7 100644

> --- a/drivers/irqchip/qcom-pdc.c

> +++ b/drivers/irqchip/qcom-pdc.c

> @@ -36,6 +36,7 @@ struct pdc_pin_region {

>         u32 cnt;

>  };

>

> +static DECLARE_BITMAP(pdc_wake_irqs, PDC_MAX_IRQS);

>  static DEFINE_RAW_SPINLOCK(pdc_lock);

>  static void __iomem *pdc_base;

>  static struct pdc_pin_region *pdc_region;

> @@ -87,22 +88,17 @@ static void pdc_enable_intr(struct irq_data *d, bool on)

>         raw_spin_unlock(&pdc_lock);

>  }

>

> -static void qcom_pdc_gic_disable(struct irq_data *d)

> +static int qcom_pdc_gic_set_wake(struct irq_data *d, unsigned int on)

>  {

> -       if (d->hwirq == GPIO_NO_WAKE_IRQ)

> -               return;

> -

> -       pdc_enable_intr(d, false);

> -       irq_chip_disable_parent(d);

> -}

> -

> -static void qcom_pdc_gic_enable(struct irq_data *d)

> -{

> -       if (d->hwirq == GPIO_NO_WAKE_IRQ)

> -               return;

> +       if (on) {

> +               pdc_enable_intr(d, true);

> +               irq_chip_enable_parent(d);

> +               set_bit(d->hwirq, pdc_wake_irqs);

> +       } else {

> +               clear_bit(d->hwirq, pdc_wake_irqs);

> +       }

>

> -       pdc_enable_intr(d, true);

> -       irq_chip_enable_parent(d);

> +       return irq_chip_set_wake_parent(d, on);

>  }

>

>  static void qcom_pdc_gic_mask(struct irq_data *d)

> @@ -111,6 +107,9 @@ static void qcom_pdc_gic_mask(struct irq_data *d)

>                 return;

>

>         irq_chip_mask_parent(d);

> +

> +       if (!test_bit(d->hwirq, pdc_wake_irqs))

> +               pdc_enable_intr(d, false);


I _think_ this will break masking, right?  In other words, consider
the following (having nothing to do with suspend/resume):

1. Driver requests an interrupt.
2. Driver masks interrupt (calls disable_irq())
3. Interrupt fires while it is masked.
4. Driver unmasks interrupt (calls enable_irq().

After step #4 the interrupt should fire since it was only masked, not
disabled (yes, it's super confusing that the driver calls
disable_irq() but it expecting it to be masked--as I understand it
that's just how it is).  I haven't tested, but I suspect that's broken
for you now (assuming you're working on a pin that wasn't a wakeup
pin) because you won't track edges when you're "disabled".

I suspect that the right thing to do here is to:

a) Make qcom_pdc_gic_set_wake() just keep "pdc_wake_irqs" up to date
and then call parent.

b) Implement irq_suspend and irq_resume.  In irq_suspend() you disable
all interrupts that aren't in "pdc_wake_irqs".  In irq_resume() you
just re-enable all of them (masking will be handled by the parent).

Would that work?

...oh, drat!  The .irq_suspend() callback is only there if you're
using "irq/generic-chip.c".  OK, well unless we want to move over to
using generic-chip we can just register for syscore ourselves.  OK, I
tested and <https://crrev.com/c/2296160> works.



>  }

>

>  static void qcom_pdc_gic_unmask(struct irq_data *d)

> @@ -118,6 +117,7 @@ static void qcom_pdc_gic_unmask(struct irq_data *d)

>         if (d->hwirq == GPIO_NO_WAKE_IRQ)

>                 return;

>

> +       pdc_enable_intr(d, true);

>         irq_chip_unmask_parent(d);

>  }

>

> @@ -197,15 +197,13 @@ static struct irq_chip qcom_pdc_gic_chip = {

>         .irq_eoi                = irq_chip_eoi_parent,

>         .irq_mask               = qcom_pdc_gic_mask,

>         .irq_unmask             = qcom_pdc_gic_unmask,

> -       .irq_disable            = qcom_pdc_gic_disable,

> -       .irq_enable             = qcom_pdc_gic_enable,

>         .irq_get_irqchip_state  = qcom_pdc_gic_get_irqchip_state,

>         .irq_set_irqchip_state  = qcom_pdc_gic_set_irqchip_state,

>         .irq_retrigger          = irq_chip_retrigger_hierarchy,

>         .irq_set_type           = qcom_pdc_gic_set_type,

> +       .irq_set_wake           = qcom_pdc_gic_set_wake,

>         .flags                  = IRQCHIP_MASK_ON_SUSPEND |

> -                                 IRQCHIP_SET_TYPE_MASKED |

> -                                 IRQCHIP_SKIP_SET_WAKE,

> +                                 IRQCHIP_SET_TYPE_MASKED,

>         .irq_set_vcpu_affinity  = irq_chip_set_vcpu_affinity_parent,

>         .irq_set_affinity       = irq_chip_set_affinity_parent,

>  };

> --

> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member

> of Code Aurora Forum, hosted by The Linux Foundation

>
diff mbox series

Patch

diff --git a/drivers/irqchip/qcom-pdc.c b/drivers/irqchip/qcom-pdc.c
index 6ae9e1f..8beb6f7 100644
--- a/drivers/irqchip/qcom-pdc.c
+++ b/drivers/irqchip/qcom-pdc.c
@@ -36,6 +36,7 @@  struct pdc_pin_region {
 	u32 cnt;
 };
 
+static DECLARE_BITMAP(pdc_wake_irqs, PDC_MAX_IRQS);
 static DEFINE_RAW_SPINLOCK(pdc_lock);
 static void __iomem *pdc_base;
 static struct pdc_pin_region *pdc_region;
@@ -87,22 +88,17 @@  static void pdc_enable_intr(struct irq_data *d, bool on)
 	raw_spin_unlock(&pdc_lock);
 }
 
-static void qcom_pdc_gic_disable(struct irq_data *d)
+static int qcom_pdc_gic_set_wake(struct irq_data *d, unsigned int on)
 {
-	if (d->hwirq == GPIO_NO_WAKE_IRQ)
-		return;
-
-	pdc_enable_intr(d, false);
-	irq_chip_disable_parent(d);
-}
-
-static void qcom_pdc_gic_enable(struct irq_data *d)
-{
-	if (d->hwirq == GPIO_NO_WAKE_IRQ)
-		return;
+	if (on) {
+		pdc_enable_intr(d, true);
+		irq_chip_enable_parent(d);
+		set_bit(d->hwirq, pdc_wake_irqs);
+	} else {
+		clear_bit(d->hwirq, pdc_wake_irqs);
+	}
 
-	pdc_enable_intr(d, true);
-	irq_chip_enable_parent(d);
+	return irq_chip_set_wake_parent(d, on);
 }
 
 static void qcom_pdc_gic_mask(struct irq_data *d)
@@ -111,6 +107,9 @@  static void qcom_pdc_gic_mask(struct irq_data *d)
 		return;
 
 	irq_chip_mask_parent(d);
+
+	if (!test_bit(d->hwirq, pdc_wake_irqs))
+		pdc_enable_intr(d, false);
 }
 
 static void qcom_pdc_gic_unmask(struct irq_data *d)
@@ -118,6 +117,7 @@  static void qcom_pdc_gic_unmask(struct irq_data *d)
 	if (d->hwirq == GPIO_NO_WAKE_IRQ)
 		return;
 
+	pdc_enable_intr(d, true);
 	irq_chip_unmask_parent(d);
 }
 
@@ -197,15 +197,13 @@  static struct irq_chip qcom_pdc_gic_chip = {
 	.irq_eoi		= irq_chip_eoi_parent,
 	.irq_mask		= qcom_pdc_gic_mask,
 	.irq_unmask		= qcom_pdc_gic_unmask,
-	.irq_disable		= qcom_pdc_gic_disable,
-	.irq_enable		= qcom_pdc_gic_enable,
 	.irq_get_irqchip_state	= qcom_pdc_gic_get_irqchip_state,
 	.irq_set_irqchip_state	= qcom_pdc_gic_set_irqchip_state,
 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
 	.irq_set_type		= qcom_pdc_gic_set_type,
+	.irq_set_wake		= qcom_pdc_gic_set_wake,
 	.flags			= IRQCHIP_MASK_ON_SUSPEND |
-				  IRQCHIP_SET_TYPE_MASKED |
-				  IRQCHIP_SKIP_SET_WAKE,
+				  IRQCHIP_SET_TYPE_MASKED,
 	.irq_set_vcpu_affinity	= irq_chip_set_vcpu_affinity_parent,
 	.irq_set_affinity	= irq_chip_set_affinity_parent,
 };