[PATCH 5.9 150/255] pinctrl: qcom: Move clearing pending IRQ to .irq_request_resources callback

Greg Kroah-Hartman
2020-11-17T13:47:37Z

From: Maulik Shah <mkshah@codeaurora.org>

[ Upstream commit 71266d9d39366c9b24b866d811b3facaf837f13f ]

When GPIOs that are routed to PDC are used as output they can still latch
the IRQ pending at GIC. As a result the spurious IRQ was handled when the
client driver change the direction to input to starts using it as IRQ.

Currently such erroneous latched IRQ are cleared with .irq_enable callback
however if the driver continue to use GPIO as interrupt and invokes
disable_irq() followed by enable_irq() then everytime during enable_irq()
previously latched interrupt gets cleared.

This can make edge IRQs not seen after enable_irq() if they had arrived
after the driver has invoked disable_irq() and were pending at GIC.

Move clearing erroneous IRQ to .irq_request_resources callback as this is
the place where GPIO direction is changed as input and its locked as IRQ.

While at this add a missing check to invoke msm_gpio_irq_clear_unmask()
from .irq_enable callback only when GPIO is not routed to PDC.

Fixes: e35a6ae0eb3a ("pinctrl/msm: Setup GPIO chip in hierarchy")
Signed-off-by: Maulik Shah <mkshah@codeaurora.org>
Link: https://lore.kernel.org/r/1604561884-10166-1-git-send-email-mkshah@codeaurora.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/pinctrl/qcom/pinctrl-msm.c | 32 ++++++++++++++++++------------
1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c
index 1df232266f63a..1554f0275067e 100644
--- a/drivers/pinctrl/qcom/pinctrl-msm.c
+++ b/drivers/pinctrl/qcom/pinctrl-msm.c
@@ -815,21 +815,14 @@ static void msm_gpio_irq_clear_unmask(struct irq_data *d, bool status_clear)

static void msm_gpio_irq_enable(struct irq_data *d)
{
- /*
- * Clear the interrupt that may be pending before we enable
- * the line.
- * This is especially a problem with the GPIOs routed to the
- * PDC. These GPIOs are direct-connect interrupts to the GIC.
- * Disabling the interrupt line at the PDC does not prevent
- * the interrupt from being latched at the GIC. The state at
- * GIC needs to be cleared before enabling.
- */
- if (d->parent_data) {
- irq_chip_set_parent_state(d, IRQCHIP_STATE_PENDING, 0);
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct msm_pinctrl *pctrl = gpiochip_get_data(gc);
+
+ if (d->parent_data)
irq_chip_enable_parent(d);
- }

- msm_gpio_irq_clear_unmask(d, true);
+ if (!test_bit(d->hwirq, pctrl->skip_wake_irqs))
+ msm_gpio_irq_clear_unmask(d, true);
}

static void msm_gpio_irq_disable(struct irq_data *d)
@@ -1104,6 +1097,19 @@ static int msm_gpio_irq_reqres(struct irq_data *d)
ret = -EINVAL;
goto out;
}
+
+ /*
+ * Clear the interrupt that may be pending before we enable
+ * the line.
+ * This is especially a problem with the GPIOs routed to the
+ * PDC. These GPIOs are direct-connect interrupts to the GIC.
+ * Disabling the interrupt line at the PDC does not prevent
+ * the interrupt from being latched at the GIC. The state at
+ * GIC needs to be cleared before enabling.
+ */
+ if (d->parent_data && test_bit(d->hwirq, pctrl->skip_wake_irqs))
+ irq_chip_set_parent_state(d, IRQCHIP_STATE_PENDING, 0);
+
return 0;
out:
module_put(gc->owner);
--
2.27.0