Re: [PATCH v2] gpio: mxc: Shift generic request/free after gpiochip registration
From: Linus Walleij <hidden>
Date: 2016-11-01 22:55:59
On Tue, Oct 25, 2016 at 8:02 PM, Deepak Das [off-list ref] wrote:
generic gpio request/free should be added after gpiocip registration to validate mapping of gpiochip with pinctrl subsystem. gpiochip->pin_ranges list contains the information used by pinctrl subsystem to configure corresponding pins for gpio usage. This list will be empty if gpiochip fails to map with pinctrl subsystem for any reason. For Ex.:- generic gpio request/free should not be used if IOMUX pin controller device node is disabled in device tree. This commit checks above list and skips adding generic gpio request/free if list is found empty. Signed-off-by: Deepak Das <redacted> Signed-off-by: Vladimir Zapolskiy <redacted>
So we should not dereference gpiolib internals.
quoted hunk ↗ jump to hunk
- if (of_property_read_bool(np, "gpio-ranges")) { - port->gc.request = gpiochip_generic_request; - port->gc.free = gpiochip_generic_free; - } - port->gc.to_irq = mxc_gpio_to_irq; port->gc.base = (pdev->id < 0) ? of_alias_get_id(np, "gpio") * 32 : pdev->id * 32;@@ -471,6 +466,11 @@ static int mxc_gpio_probe(struct platform_device *pdev) if (err) goto out_bgio; + if (!list_empty(&port->gc.pin_ranges)) { + port->gc.request = gpiochip_generic_request; + port->gc.free = gpiochip_generic_free; + }
Can't you just check the "gpio-ranges" property later instead? Yours, Linus Walleij