openwrt/target/linux/bcm27xx/patches-6.6/950-0443-pinctrl-bcm2835-Workaround-for-edge-IRQ-loss.patch
Álvaro Fernández Rojas 8c405cdccc bcm27xx: add 6.6 kernel patches
The patches were generated from the RPi repo with the following command:
git format-patch v6.6.34..rpi-6.1.y

Some patches needed rebasing and, as usual, the applied and reverted, wireless
drivers, Github workflows, READMEs and defconfigs patches were removed.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2024-06-18 18:52:49 +02:00

68 lines
2.3 KiB
Diff

From 60610341f26017aecb77bd3b23d2b51b1e918e94 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
Date: Fri, 5 May 2023 11:25:48 +0100
Subject: [PATCH 0443/1085] pinctrl: bcm2835: Workaround for edge IRQ loss
It has been observed that edge events can be lost when GPIO edges occur
close to each other. Investigation suggests this is due to a hardware
bug, although no mechanism has been identified.
Work around the event loss by moving the IRQ acknowledgement into the
main ISR, adding missing events by explicit level-change detection.
See: https://forums.raspberrypi.com/viewtopic.php?t=350295
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
---
drivers/pinctrl/bcm/pinctrl-bcm2835.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
--- a/drivers/pinctrl/bcm/pinctrl-bcm2835.c
+++ b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
@@ -420,15 +420,32 @@ static void bcm2835_gpio_irq_handle_bank
unsigned long events;
unsigned offset;
unsigned gpio;
+ u32 levs, levs2;
events = bcm2835_gpio_rd(pc, GPEDS0 + bank * 4);
+ levs = bcm2835_gpio_rd(pc, GPLEV0 + bank * 4);
events &= mask;
events &= pc->enabled_irq_map[bank];
+ bcm2835_gpio_wr(pc, GPEDS0 + bank * 4, events);
+
+retry:
for_each_set_bit(offset, &events, 32) {
gpio = (32 * bank) + offset;
generic_handle_domain_irq(pc->gpio_chip.irq.domain,
gpio);
}
+ events = bcm2835_gpio_rd(pc, GPEDS0 + bank * 4);
+ levs2 = bcm2835_gpio_rd(pc, GPLEV0 + bank * 4);
+
+ events |= levs2 & ~levs & bcm2835_gpio_rd(pc, GPREN0 + bank * 4);
+ events |= ~levs2 & levs & bcm2835_gpio_rd(pc, GPFEN0 + bank * 4);
+ events &= mask;
+ events &= pc->enabled_irq_map[bank];
+ if (events) {
+ bcm2835_gpio_wr(pc, GPEDS0 + bank * 4, events);
+ levs = levs2;
+ goto retry;
+ }
}
static void bcm2835_gpio_irq_handler(struct irq_desc *desc)
@@ -668,11 +685,7 @@ static int bcm2835_gpio_irq_set_type(str
static void bcm2835_gpio_irq_ack(struct irq_data *data)
{
- struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
- struct bcm2835_pinctrl *pc = gpiochip_get_data(chip);
- unsigned gpio = irqd_to_hwirq(data);
-
- bcm2835_gpio_set_bit(pc, GPEDS0, gpio);
+ /* Nothing to do - the main interrupt handler includes the ACK */
}
static int bcm2835_gpio_irq_set_wake(struct irq_data *data, unsigned int on)