[PATCH 4.14 074/109] pinctrl: mcp23s08: fix irq and irqchip setup order

Greg Kroah-Hartman
2018-10-16T17:20:33Z

From: Marco Felsch <m.felsch@pengutronix.de>

commit f259f896f2348f0302f6f88d4382378cf9d23a7e upstream.

Since 'commit 02e389e63e35 ("pinctrl: mcp23s08: fix irq setup order")' the
irq request isn't the last devm_* allocation. Without a deeper look at
the irq and testing this isn't a good solution. Since this driver relies
on the devm mechanism, requesting a interrupt should be the last thing
to avoid memory corruptions during unbinding.

'Commit 02e389e63e35 ("pinctrl: mcp23s08: fix irq setup order")' fixed the
order for the interrupt-controller use case only. The
mcp23s08_irq_setup() must be split into two to fix it for the
interrupt-controller use case and to register the irq at last. So the
irq will be freed first during unbind.

Cc: stable@vger.kernel.org
Cc: Jan Kundrát <jan.kundrat@cesnet.cz>
Cc: Dmitry Mastykin <mastichi@gmail.com>
Cc: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Fixes: 82039d244f87 ("pinctrl: mcp23s08: add pinconf support")
Fixes: 02e389e63e35 ("pinctrl: mcp23s08: fix irq setup order")
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Tested-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/pinctrl/pinctrl-mcp23s08.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)

--- a/drivers/pinctrl/pinctrl-mcp23s08.c
+++ b/drivers/pinctrl/pinctrl-mcp23s08.c
@@ -643,6 +643,14 @@ static int mcp23s08_irq_setup(struct mcp
return err;
}

+ return 0;
+}
+
+static int mcp23s08_irqchip_setup(struct mcp23s08 *mcp)
+{
+ struct gpio_chip *chip = &mcp->chip;
+ int err;
+
err = gpiochip_irqchip_add_nested(chip,
&mcp23s08_irq_chip,
0,
@@ -907,7 +915,7 @@ static int mcp23s08_probe_one(struct mcp
}

if (mcp->irq && mcp->irq_controller) {
- ret = mcp23s08_irq_setup(mcp);
+ ret = mcp23s08_irqchip_setup(mcp);
if (ret)
goto fail;
}
@@ -932,6 +940,9 @@ static int mcp23s08_probe_one(struct mcp
goto fail;
}

+ if (mcp->irq)
+ ret = mcp23s08_irq_setup(mcp);
+
fail:
if (ret < 0)
dev_dbg(dev, "can't setup chip %d, --> %d\n", addr, ret);