Re: [PATCH v2 04/10] pinctrl: sunxi: Prepare for building SoC specific drivers as modules

Maxime Ripard
2015-05-19T08:20:11Z

[-- Attachment #1: Type: text/plain, Size: 3755 bytes --]

On Tue, May 19, 2015 at 04:02:39PM +0800, Chen-Yu Tsai wrote:
> On Tue, May 19, 2015 at 3:55 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > On Mon, May 18, 2015 at 11:32:31AM +0200, Jens Kuske wrote:
> >> Hi,
> >>
> >> On 05/17/15 16:19, Maxime Ripard wrote:
> >> > On Fri, May 15, 2015 at 06:38:54PM +0200, Jens Kuske wrote:
> >> >> Add a remove function and export the init and remove function
> >> >> to allow us to build the SoC specific drivers as modules.
> >> >>
> >> >> Signed-off-by: Jens Kuske <jenskuske@gmail.com>
> >> >> ---
> >> >> drivers/pinctrl/sunxi/pinctrl-sunxi.c | 25 +++++++++++++++++++------
> >> >> drivers/pinctrl/sunxi/pinctrl-sunxi.h | 2 ++
> >> >> 2 files changed, 21 insertions(+), 6 deletions(-)
> >> >>
> >> >> diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
> >> >> index f8e171b..4ef6b3d 100644
> >> >> --- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
> >> >> +++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
> >> >> @@ -856,7 +856,6 @@ int sunxi_pinctrl_init(struct platform_device *pdev,
> >> >> struct sunxi_pinctrl *pctl;
> >> >> struct resource *res;
> >> >> int i, ret, last_pin;
> >> >> - struct clk *clk;
> >> >>
> >> >> pctl = devm_kzalloc(&pdev->dev, sizeof(*pctl), GFP_KERNEL);
> >> >> if (!pctl)
> >> >> @@ -954,13 +953,13 @@ int sunxi_pinctrl_init(struct platform_device *pdev,
> >> >> goto gpiochip_error;
> >> >> }
> >> >>
> >> >> - clk = devm_clk_get(&pdev->dev, NULL);
> >> >> - if (IS_ERR(clk)) {
> >> >> - ret = PTR_ERR(clk);
> >> >> + pctl->clk = devm_clk_get(&pdev->dev, NULL);
> >> >> + if (IS_ERR(pctl->clk)) {
> >> >> + ret = PTR_ERR(pctl->clk);
> >> >> goto gpiochip_error;
> >> >> }
> >> >>
> >> >> - ret = clk_prepare_enable(clk);
> >> >> + ret = clk_prepare_enable(pctl->clk);
> >> >> if (ret)
> >> >> goto gpiochip_error;
> >> >>
> >> >> @@ -1015,10 +1014,24 @@ int sunxi_pinctrl_init(struct platform_device *pdev,
> >> >> return 0;
> >> >>
> >> >> clk_error:
> >> >> - clk_disable_unprepare(clk);
> >> >> + clk_disable_unprepare(pctl->clk);
> >> >> gpiochip_error:
> >> >> gpiochip_remove(pctl->chip);
> >> >> pinctrl_error:
> >> >> pinctrl_unregister(pctl->pctl_dev);
> >> >> return ret;
> >> >> }
> >> >> +EXPORT_SYMBOL(sunxi_pinctrl_init);
> >> >> +
> >> >> +int sunxi_pinctrl_remove(struct platform_device *pdev)
> >> >> +{
> >> >> + struct sunxi_pinctrl *pctl = platform_get_drvdata(pdev);
> >> >> +
> >> >> + gpiochip_remove(pctl->chip);
> >> >> + pinctrl_unregister(pctl->pctl_dev);
> >> >> +
> >> >> + clk_disable_unprepare(pctl->clk);
> >> >
> >> > We should also remove the domain and the interrupt mapping here.
> >>
> >> Ouch, I missed that. Only looked at the *_error: labels.
> >>
> >> Apart from that, currently the kernel panics some seconds after removing
> >> the pinctrl module because mmc wants to access a gpio. Can this be
> >> prevented somehow? I think pinctrl must not be removed once other
> >> devices use any pin-related things.
> >
> > pinctrl_unregister doesn't look like it cares about whether or not
> > there's users left in the system.
> >
> > Maybe the easiest path would be to just make this builtin like Paul
> > suggested then ... :/
>
> Is there a way to mark modules as not removable? At least we can keep
> the multi-platform kernel image small.

If there's no module_exit, the module will only be removable through a
rmmod -f, which seems like an acceptable solution.

Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]