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

Chen-Yu Tsai
2015-05-19T08:03:15Z

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.