4.4-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 7ae710f9f8b2cf95297e7bbfe1c09789a7dc43d4 ]
On SoC reset all GPIO interrupts are disable. However, if kexec is used to boot into a new kernel, the SoC does not experience a reset. Hence GPIO interrupts can be left enabled from the previous kernel. It is then possible for the interrupt to fire before an interrupt handler is registered, resulting in the kernel complaining of an "unexpected IRQ trap", the interrupt is never cleared, and so fires again, resulting in an interrupt storm.
Disable all GPIO interrupts before registering the GPIO IRQ chip.
Fixes: 7f2691a19627 ("gpio: vf610: add gpiolib/IRQ chip driver for Vybrid") Signed-off-by: Andrew Lunn andrew@lunn.ch Acked-by: Stefan Agner stefan@agner.ch Signed-off-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpio/gpio-vf610.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/gpio/gpio-vf610.c b/drivers/gpio/gpio-vf610.c index 87b950cec6ec..db95c4b99a74 100644 --- a/drivers/gpio/gpio-vf610.c +++ b/drivers/gpio/gpio-vf610.c @@ -227,6 +227,7 @@ static int vf610_gpio_probe(struct platform_device *pdev) struct vf610_gpio_port *port; struct resource *iores; struct gpio_chip *gc; + int i; int ret;
port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL); @@ -265,6 +266,10 @@ static int vf610_gpio_probe(struct platform_device *pdev) if (ret < 0) return ret;
+ /* Mask all GPIO interrupts */ + for (i = 0; i < gc->ngpio; i++) + vf610_gpio_writel(0, port->base + PORT_PCR(i)); + /* Clear the interrupt status register for all GPIO's */ vf610_gpio_writel(~0, port->base + PORT_ISFR);