| Message ID | 1473299296-22458-3-git-send-email-vladimir_zapolskiy@mentor.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Sep 8, 2016 at 3:48 AM, Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> wrote: > In general situation on-SoC GPIO controller drivers should be probed > after pinctrl/pinmux controller driver, because on-SoC GPIOs utilize a > pin/pad as a resource provided and controlled by pinctrl subsystem. > > This is stated in multiple places, e.g. from drivers/Makefile: > > GPIO must come after pinctrl as gpios may need to mux pins etc > > Looking at Freescale iMX SoC series specifics, imx*_pinctrl_init() > functions are called at arch_initcall and postcore_initcall init > levels, so the change of initcall level for gpio-mxc driver from > postcore_initcall to subsys_initcall level is sufficient. Also note > that the most of GPIO controller drivers settled at subsys_initcall > level. > > If pinctrl subsystem manages pads with GPIO functions, the change is > needed to avoid unwanted driver probe deferrals during kernel boot. > > Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> > --- > Changes from v1 to v2: > * replaced by a change with better commit description and which > moves gpio_mxc_init() call to subsys_initcall() instead of > apparently too late device_initcall(), this mitigates Shawn's > expressed concern about the change. Patch applied with Shawn's ACK. Yours, Linus Walleij
diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c index 1b342a3842c8..1fdd5d804b5b 100644 --- a/drivers/gpio/gpio-mxc.c +++ b/drivers/gpio/gpio-mxc.c @@ -510,7 +510,7 @@ static int __init gpio_mxc_init(void) { return platform_driver_register(&mxc_gpio_driver); } -postcore_initcall(gpio_mxc_init); +subsys_initcall(gpio_mxc_init); MODULE_AUTHOR("Freescale Semiconductor, " "Daniel Mack <danielncaiaq.de>, "
In general situation on-SoC GPIO controller drivers should be probed after pinctrl/pinmux controller driver, because on-SoC GPIOs utilize a pin/pad as a resource provided and controlled by pinctrl subsystem. This is stated in multiple places, e.g. from drivers/Makefile: GPIO must come after pinctrl as gpios may need to mux pins etc Looking at Freescale iMX SoC series specifics, imx*_pinctrl_init() functions are called at arch_initcall and postcore_initcall init levels, so the change of initcall level for gpio-mxc driver from postcore_initcall to subsys_initcall level is sufficient. Also note that the most of GPIO controller drivers settled at subsys_initcall level. If pinctrl subsystem manages pads with GPIO functions, the change is needed to avoid unwanted driver probe deferrals during kernel boot. Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> --- Changes from v1 to v2: * replaced by a change with better commit description and which moves gpio_mxc_init() call to subsys_initcall() instead of apparently too late device_initcall(), this mitigates Shawn's expressed concern about the change. drivers/gpio/gpio-mxc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)