6.1-stable review patch. If anyone has any objections, please let me know.
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From: Sergey Matsievskiy matsievskiysv@gmail.com
commit 93b8ddc54507a227087c60a0013ed833b6ae7d3c upstream.
The current implementation only calls chained_irq_enter() and chained_irq_exit() if it detects pending interrupts.
``` for (i = 0; i < info->stride; i++) { uregmap_read(info->map, id_reg + 4 * i, ®); if (!reg) continue;
chained_irq_enter(parent_chip, desc); ```
However, in case of GPIO pin configured in level mode and the parent controller configured in edge mode, GPIO interrupt might be lowered by the hardware. In the result, if the interrupt is short enough, the parent interrupt is still pending while the GPIO interrupt is cleared; chained_irq_enter() never gets called and the system hangs trying to service the parent interrupt.
Moving chained_irq_enter() and chained_irq_exit() outside the for loop ensures that they are called even when GPIO interrupt is lowered by the hardware.
The similar code with chained_irq_enter() / chained_irq_exit() functions wrapping interrupt checking loop may be found in many other drivers: ``` grep -r -A 10 chained_irq_enter drivers/pinctrl ```
Cc: stable@vger.kernel.org Signed-off-by: Sergey Matsievskiy matsievskiysv@gmail.com Reviewed-by: Alexandre Belloni alexandre.belloni@bootlin.com Link: https://lore.kernel.org/20241012105743.12450-2-matsievskiysv@gmail.com Signed-off-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pinctrl/pinctrl-ocelot.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/pinctrl/pinctrl-ocelot.c +++ b/drivers/pinctrl/pinctrl-ocelot.c @@ -1962,21 +1962,21 @@ static void ocelot_irq_handler(struct ir unsigned int reg = 0, irq, i; unsigned long irqs;
+ chained_irq_enter(parent_chip, desc); + for (i = 0; i < info->stride; i++) { regmap_read(info->map, id_reg + 4 * i, ®); if (!reg) continue;
- chained_irq_enter(parent_chip, desc); - irqs = reg;
for_each_set_bit(irq, &irqs, min(32U, info->desc->npins - 32 * i)) generic_handle_domain_irq(chip->irq.domain, irq + 32 * i); - - chained_irq_exit(parent_chip, desc); } + + chained_irq_exit(parent_chip, desc); }
static int ocelot_gpiochip_register(struct platform_device *pdev,