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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAGb2v6608XVsxN0f2DEmqmts1zDo223t+fBv46WjGQVQbw7+CA@mail.gmail.com>
Date:	Tue, 19 May 2015 16:02:39 +0800
From:	Chen-Yu Tsai <wens@...e.org>
To:	Maxime Ripard <maxime.ripard@...e-electrons.com>
Cc:	Jens Kuske <jenskuske@...il.com>,
	Emilio López <emilio@...pez.com.ar>,
	Mike Turquette <mturquette@...aro.org>,
	Linus Walleij <linus.walleij@...aro.org>,
	Rob Herring <robh+dt@...nel.org>, Chen-Yu Tsai <wens@...e.org>,
	Vishnu Patekar <vishnupatekar0510@...il.com>,
	Hans de Goede <hdegoede@...hat.com>,
	devicetree <devicetree@...r.kernel.org>,
	linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	linux-sunxi <linux-sunxi@...glegroups.com>
Subject: Re: [PATCH v2 04/10] pinctrl: sunxi: Prepare for building SoC
 specific drivers as modules

On Tue, May 19, 2015 at 3:55 PM, Maxime Ripard
<maxime.ripard@...e-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@...il.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.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/