From: Daniel Thompson daniel.thompson@linaro.org
[ Upstream commit 4efc851c36e389f7ed432edac0149acc5f94b0c7 ]
Currently the EXIU uses the fasteoi interrupt flow that is configured by it's parent (irq-gic-v3.c). With this flow the only chance to clear the interrupt request happens during .irq_eoi() and (obviously) this happens after the interrupt handler has run. EXIU requires edge triggered interrupts to be acked prior to interrupt handling. Without this we risk incorrect interrupt dismissal when a new interrupt is delivered after the handler reads and acknowledges the peripheral but before the irq_eoi() takes place.
Fix this by clearing the interrupt request from .irq_ack() if we are configured for edge triggered interrupts. This requires adopting the fasteoi-ack flow instead of the fasteoi to ensure the ack gets called.
These changes have been tested using the power button on a Developerbox/SC2A11 combined with some hackery in gpio-keys so I can play with the different trigger mode [and an mdelay(500) so I can can check what happens on a double click in both modes].
Fixes: 706cffc1b912 ("irqchip/exiu: Add support for Socionext Synquacer EXIU controller") Signed-off-by: Daniel Thompson daniel.thompson@linaro.org Reviewed-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20220503134541.2566457-1-daniel.thompson@linaro.or... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/Kconfig.platforms | 1 + drivers/irqchip/irq-sni-exiu.c | 25 ++++++++++++++++++++++--- 2 files changed, 23 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms index 21697449d762..14602e0e024e 100644 --- a/arch/arm64/Kconfig.platforms +++ b/arch/arm64/Kconfig.platforms @@ -253,6 +253,7 @@ config ARCH_INTEL_SOCFPGA
config ARCH_SYNQUACER bool "Socionext SynQuacer SoC Family" + select IRQ_FASTEOI_HIERARCHY_HANDLERS
config ARCH_TEGRA bool "NVIDIA Tegra SoC Family" diff --git a/drivers/irqchip/irq-sni-exiu.c b/drivers/irqchip/irq-sni-exiu.c index abd011fcecf4..c7db617e1a2f 100644 --- a/drivers/irqchip/irq-sni-exiu.c +++ b/drivers/irqchip/irq-sni-exiu.c @@ -37,11 +37,26 @@ struct exiu_irq_data { u32 spi_base; };
-static void exiu_irq_eoi(struct irq_data *d) +static void exiu_irq_ack(struct irq_data *d) { struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
writel(BIT(d->hwirq), data->base + EIREQCLR); +} + +static void exiu_irq_eoi(struct irq_data *d) +{ + struct exiu_irq_data *data = irq_data_get_irq_chip_data(d); + + /* + * Level triggered interrupts are latched and must be cleared during + * EOI or the interrupt will be jammed on. Of course if a level + * triggered interrupt is still asserted then the write will not clear + * the interrupt. + */ + if (irqd_is_level_type(d)) + writel(BIT(d->hwirq), data->base + EIREQCLR); + irq_chip_eoi_parent(d); }
@@ -91,10 +106,13 @@ static int exiu_irq_set_type(struct irq_data *d, unsigned int type) writel_relaxed(val, data->base + EILVL);
val = readl_relaxed(data->base + EIEDG); - if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH) + if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH) { val &= ~BIT(d->hwirq); - else + irq_set_handler_locked(d, handle_fasteoi_irq); + } else { val |= BIT(d->hwirq); + irq_set_handler_locked(d, handle_fasteoi_ack_irq); + } writel_relaxed(val, data->base + EIEDG);
writel_relaxed(BIT(d->hwirq), data->base + EIREQCLR); @@ -104,6 +122,7 @@ static int exiu_irq_set_type(struct irq_data *d, unsigned int type)
static struct irq_chip exiu_irq_chip = { .name = "EXIU", + .irq_ack = exiu_irq_ack, .irq_eoi = exiu_irq_eoi, .irq_enable = exiu_irq_enable, .irq_mask = exiu_irq_mask,