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authorMarc Zyngier <maz@kernel.org>2020-10-05 15:02:17 +0100
committerLinus Walleij <linus.walleij@linaro.org>2020-10-07 11:47:41 +0200
commit8b81edd80baf12d64420daff1759380aa9a14998 (patch)
tree9d168af1a0db163e24a5f79afd4c88f172dc1831
parent47e538d86d5776ac8152146c3ed3d22326243190 (diff)
gpio: pca953x: Survive spurious interrupts
The pca953x driver never checks the result of irq_find_mapping(), which returns 0 when no mapping is found. When a spurious interrupt is delivered (which can happen under obscure circumstances), the kernel explodes as it still tries to handle the error code as a real interrupt. Handle this particular case and warn on spurious interrupts. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201005140217.1390851-1-maz@kernel.org Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
-rw-r--r--drivers/gpio/gpio-pca953x.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index fb61f2fc6ed7..c2d6121c48c9 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -824,8 +824,21 @@ static irqreturn_t pca953x_irq_handler(int irq, void *devid)
ret = pca953x_irq_pending(chip, pending);
mutex_unlock(&chip->i2c_lock);
- for_each_set_bit(level, pending, gc->ngpio)
- handle_nested_irq(irq_find_mapping(gc->irq.domain, level));
+ if (ret) {
+ ret = 0;
+
+ for_each_set_bit(level, pending, gc->ngpio) {
+ int nested_irq = irq_find_mapping(gc->irq.domain, level);
+
+ if (unlikely(nested_irq <= 0)) {
+ dev_warn_ratelimited(gc->parent, "unmapped interrupt %d\n", level);
+ continue;
+ }
+
+ handle_nested_irq(nested_irq);
+ ret = 1;
+ }
+ }
return IRQ_RETVAL(ret);
}