pinctrl: mcp23s08: fix irq and irqchip setup order

BugLink: https://bugs.launchpad.net/bugs/1836426
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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/pinctrl/pinctrl-mcp23s08.c b/drivers/pinctrl/pinctrl-mcp23s08.c
index 03ee9be2bb30adef285b0210e8874111d6420df4..54c8cbc660211d81c3d7bb08f43ee8bb9a79f649 100644 (file)
--- a/drivers/pinctrl/pinctrl-mcp23s08.c
+++ b/drivers/pinctrl/pinctrl-mcp23s08.c
@@ -641,6 +641,14 @@ static int mcp23s08_irq_setup(struct mcp23s08 *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,
@@ -912,7 +920,7 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
        }
 
        if (mcp->irq && mcp->irq_controller) {
-               ret = mcp23s08_irq_setup(mcp);
+               ret = mcp23s08_irqchip_setup(mcp);
                if (ret)
                        goto fail;
        }
@@ -937,6 +945,9 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
                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);