On 13.07.2026 21:13, Mitchell Horne wrote:
The branch main has been updated by mhorne:
URL:
https://cgit.FreeBSD.org/src/commit/?id=8ffb400bfd64102ac2a49639ccbbfffbe0c6f127
commit 8ffb400bfd64102ac2a49639ccbbfffbe0c6f127
Author: Kyle Crenshaw <[email protected]>
AuthorDate: 2026-05-29 22:22:39 +0000
Commit: Mitchell Horne <[email protected]>
CommitDate: 2026-07-13 19:07:52 +0000
rk_gpio: defer level-IRQ EOI until source line is driven low
The previous PIC bring-up (ccda002ca10) added pic_disable_intr,
pic_enable_intr, pic_pre_ithread, and pic_post_ithread, but omitted
pic_post_filter. Per the PIC contract pic_post_filter is non-optional;
a follow-up enforcement pass is planned that will panic() if any of the
three (pic_pre_ithread, pic_post_ithread, pic_post_filter) is missing.
This patch also fixes the EOI ordering for level-triggered IRQs (raised
by mhorne in the v1 review). Writing PORTA_EOI before intr_isrc_dispatch
is correct for edge pins, but wrong for level pins: the source device
has not yet deasserted the line, so the latch immediately re-arms and
the controller storms.
- rk_gpio_intr: EOI edge pins per-pin before dispatch (matches the
pre-patch behavior for the common case); for level pins defer EOI
to the post-dispatch path. Stray (no consumer) level pins still
get EOI'd here because no consumer will run to clear the source.
- rk_pic_post_filter: new method, EOI level pins after the filter
has read+cleared the source device's IRQ register.
- rk_pic_post_ithread: EOI level pins after the ithread has driven
the source low, before unmasking, so the chip latch is clean when
we re-enable delivery.
Shape mirrors tegra_gpio(4) (sys/arm/nvidia/tegra_gpio.c). No new
sysctls, no scaffolding.
Smoke-tested on RockPro64 (RK3399) with fusb302 INT_N (level-low GPIO
IRQ): IRQ rate steady at ~28/s under USB-C activity vs the 210 kHz
storm the original missing-mask bug produced.
The original rk_gpio implementation is already buggy, but this change
makes the situation worse. The modification to rk_gpio_intr() is clearly
wrong and rk_pic_post_filter() is also not fully correct.
For proper handling, the functions should behave as follows:
pre_ithread() should, in this exact order:
- mask the IRQ
- do EOI (bu only for level-sensitive interrupts)
post_ithread() should:
- unmask the IRQ
post_filter() should:
- do EOI (but only for level-sensitive interrupts)
Please revert this patch and submit the change to phabricator for review.
Thanks,
Michal
Signed-off-by: Kyle Crenshaw <[email protected]>
Reviewed by: mhorne
Fixes: ccda002ca10f ("rk_gpio: implement PIC masking methods and mask
unhandled IRQs")
Pull Request: https://github.com/freebsd/freebsd-src/pull/2245
---
sys/arm64/rockchip/rk_gpio.c | 57 +++++++++++++++++++++++++++++++++++++++++---
1 file changed, 54 insertions(+), 3 deletions(-)
diff --git a/sys/arm64/rockchip/rk_gpio.c b/sys/arm64/rockchip/rk_gpio.c
index 7c2071d2d178..8988ecf992a1 100644
--- a/sys/arm64/rockchip/rk_gpio.c
+++ b/sys/arm64/rockchip/rk_gpio.c
@@ -219,13 +219,31 @@ rk_gpio_intr(void *arg)
RK_GPIO_LOCK(sc);
status = rk_gpio_read_4(sc, RK_GPIO_INT_STATUS);
- rk_gpio_write_4(sc, RK_GPIO_PORTA_EOI, status);
RK_GPIO_UNLOCK(sc);
while (status) {
int pin = ffs(status) - 1;
+ bool is_level;
status &= ~(1 << pin);
+
+ /*
+ * Edge-triggered latches must be cleared before dispatch
+ * so a new edge during the handler still registers a new
+ * IRQ. Level-triggered latches must be cleared AFTER the
+ * consumer has deasserted the source line, otherwise the
+ * latch immediately re-arms and we storm. Edge EOI here;
+ * level EOI is deferred to pic_post_filter (filter-only
+ * consumers) or pic_post_ithread (threaded consumers).
+ */
+ is_level = (sc->isrcs[pin].mode &
+ (GPIO_INTR_LEVEL_LOW | GPIO_INTR_LEVEL_HIGH)) != 0;
+ if (!is_level) {
+ RK_GPIO_LOCK(sc);
+ rk_gpio_write_4(sc, RK_GPIO_PORTA_EOI, 1u << pin);
+ RK_GPIO_UNLOCK(sc);
+ }
+
if (intr_isrc_dispatch(RK_GPIO_ISRC(sc, pin), tf)) {
/*
* Pin asserted but no consumer is registered for it
@@ -235,14 +253,19 @@ rk_gpio_intr(void *arg)
* messages per second. Mask the pin's IRQ at the
* controller and disable further dispatches; if a
* consumer attaches later it will re-enable through
- * pic_enable_intr / rk_gpio_pic_enable_intr.
+ * pic_enable_intr / rk_gpio_pic_enable_intr. For
+ * level pins also EOI now -- there is no consumer
+ * to drive the source low.
*/
RK_GPIO_LOCK(sc);
rk_gpio_write_bit(sc, RK_GPIO_INTMASK, pin, 1);
rk_gpio_write_bit(sc, RK_GPIO_INTEN, pin, 0);
+ if (is_level)
+ rk_gpio_write_4(sc, RK_GPIO_PORTA_EOI,
+ 1u << pin);
RK_GPIO_UNLOCK(sc);
device_printf(sc->sc_dev,
- "Interrupt pin=%d unhandled — masked\n", pin);
+ "Interrupt pin=%d unhandled -- masked\n", pin);
continue;
}
@@ -931,10 +954,37 @@ rk_pic_post_ithread(device_t dev, struct intr_irqsrc *isrc)
struct rk_pin_irqsrc *rkisrc = (struct rk_pin_irqsrc *)isrc;
RK_GPIO_LOCK(sc);
+ /*
+ * Level pins: EOI now that the ithread has driven the source low,
+ * then unmask so future level transitions can fire. Edge pins
+ * already EOI'd in rk_gpio_intr before dispatch.
+ */
+ if (rkisrc->mode & (GPIO_INTR_LEVEL_LOW | GPIO_INTR_LEVEL_HIGH))
+ rk_gpio_write_4(sc, RK_GPIO_PORTA_EOI, 1u << rkisrc->irq);
rk_gpio_write_bit(sc, RK_GPIO_INTMASK, rkisrc->irq, 0);
RK_GPIO_UNLOCK(sc);
}
+/*
+ * Mirror image of pic_post_ithread for filter-only consumers: the MI
+ * interrupt framework calls this after a filter returns FILTER_HANDLED
+ * (no ithread). The filter is expected to have read+cleared the source
+ * device's IRQ status itself, so the GPIO line is now low; we EOI the
+ * level latch here. Edge pins are already EOI'd in rk_gpio_intr.
+ */
+static void
+rk_pic_post_filter(device_t dev, struct intr_irqsrc *isrc)
+{
+ struct rk_gpio_softc *sc = device_get_softc(dev);
+ struct rk_pin_irqsrc *rkisrc = (struct rk_pin_irqsrc *)isrc;
+
+ if ((rkisrc->mode & (GPIO_INTR_LEVEL_LOW | GPIO_INTR_LEVEL_HIGH)) == 0)
+ return;
+ RK_GPIO_LOCK(sc);
+ rk_gpio_write_4(sc, RK_GPIO_PORTA_EOI, 1u << rkisrc->irq);
+ RK_GPIO_UNLOCK(sc);
+}
+
static device_method_t rk_gpio_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, rk_gpio_probe),
@@ -966,6 +1016,7 @@ static device_method_t rk_gpio_methods[] = {
DEVMETHOD(pic_disable_intr, rk_pic_disable_intr),
DEVMETHOD(pic_enable_intr, rk_pic_enable_intr),
DEVMETHOD(pic_pre_ithread, rk_pic_pre_ithread),
+ DEVMETHOD(pic_post_filter, rk_pic_post_filter),
DEVMETHOD(pic_post_ithread, rk_pic_post_ithread),
/* ofw_bus interface */
