4.18-stable review patch. If anyone has any objections, please let me know.
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From: Daniel Kurtz djkurtz@chromium.org
[ Upstream commit 8bbed1eef001fdfc0ee9595f64cc4f769d265af4 ]
The AMD pinctrl driver demultiplexes GPIO interrupts and fires off their individual handlers.
If one of these GPIO irqs is configured as a level interrupt, and its downstream handler is a threaded ONESHOT interrupt, the GPIO interrupt source is masked by handle_level_irq() until the eventual return of the threaded irq handler. During this time the level GPIO interrupt status will still report as high until the actual gpio source is cleared - both in the individual GPIO interrupt status bit (INTERRUPT_STS_OFF) and in its corresponding "WAKE_INT_STATUS_REG" bit.
Thus, if another GPIO interrupt occurs during this time, amd_gpio_irq_handler() will see that the (masked-and-not-yet-cleared) level irq is still pending and incorrectly call its handler again.
To fix this, have amd_gpio_irq_handler() check for both interrupts status and mask before calling generic_handle_irq().
Note: Is it possible that this bug was the source of the interrupt storm on Ryzen when using chained interrupts before commit ba714a9c1dea85 ("pinctrl/amd: Use regular interrupt instead of chained")?
Signed-off-by: Daniel Kurtz djkurtz@chromium.org Acked-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pinctrl/pinctrl-amd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/pinctrl/pinctrl-amd.c +++ b/drivers/pinctrl/pinctrl-amd.c @@ -552,7 +552,8 @@ static irqreturn_t amd_gpio_irq_handler( /* Each status bit covers four pins */ for (i = 0; i < 4; i++) { regval = readl(regs + i); - if (!(regval & PIN_IRQ_PENDING)) + if (!(regval & PIN_IRQ_PENDING) || + !(regval & BIT(INTERRUPT_MASK_OFF))) continue; irq = irq_find_mapping(gc->irq.domain, irqnr + i); generic_handle_irq(irq);