Hello,
On Wed, Sep 22, 2021 at 11:43:00AM +0200, Uwe Kleine-König wrote:
> On i.MX7S and i.MX8M* (but not i.MX6*) the pwrkey device has an
> associated clock. Accessing the registers requires that this clock is
> enabled. Binding the driver on at least i.MX7S and i.MX8MP while not
> having the clock enabled results in a complete hang of the machine.
> (This usually only happens if snvs_pwrkey is built as a module and the
> rtc-snvs driver isn't already bound because at bootup the required clk
> is on and only gets disabled when the clk framework disables unused clks
> late during boot.)
>
> This completes the fix in commit 135be16d3505 ("ARM: dts: imx7s: add
> snvs clock to pwrkey").
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
This patch fixes a hard machine hang that occurs on an i.MX8MP based
machine in ~10% of the boot ups. In my eyes it's suitable to be applied
before v5.14 even.
Any feedback on it?
Best regards
Uwe
> ---
> drivers/input/keyboard/snvs_pwrkey.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/drivers/input/keyboard/snvs_pwrkey.c b/drivers/input/keyboard/snvs_pwrkey.c
> index 2f5e3ab5ed63..b79a559b8329 100644
> --- a/drivers/input/keyboard/snvs_pwrkey.c
> +++ b/drivers/input/keyboard/snvs_pwrkey.c
> @@ -3,6 +3,7 @@
> // Driver for the IMX SNVS ON/OFF Power Key
> // Copyright (C) 2015 Freescale Semiconductor, Inc. All Rights Reserved.
>
> +#include <linux/clk.h>
> #include <linux/device.h>
> #include <linux/err.h>
> #include <linux/init.h>
> @@ -99,6 +100,11 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
> return IRQ_HANDLED;
> }
>
> +static void imx_snvs_pwrkey_disable_clk(void *data)
> +{
> + clk_disable_unprepare(data);
> +}
> +
> static void imx_snvs_pwrkey_act(void *pdata)
> {
> struct pwrkey_drv_data *pd = pdata;
> @@ -111,6 +117,7 @@ static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
> struct pwrkey_drv_data *pdata;
> struct input_dev *input;
> struct device_node *np;
> + struct clk *clk;
> int error;
> u32 vid;
>
> @@ -134,6 +141,19 @@ static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
> dev_warn(&pdev->dev, "KEY_POWER without setting in dts\n");
> }
>
> + clk = devm_clk_get_optional(&pdev->dev, NULL);
> + if (IS_ERR(clk))
> + return dev_err_probe(&pdev->dev, PTR_ERR(clk), "Failed to get clock\n");
> +
> + error = clk_prepare_enable(clk);
> + if (error)
> + return dev_err_probe(&pdev->dev, PTR_ERR(clk), "Failed to enable clock\n");
> +
> + error = devm_add_action_or_reset(&pdev->dev, imx_snvs_pwrkey_disable_clk, clk);
> + if (error)
> + return dev_err_probe(&pdev->dev, PTR_ERR(clk),
> + "Failed to register clock cleanup handler\n");
> +
> pdata->wakeup = of_property_read_bool(np, "wakeup-source");
>
> pdata->irq = platform_get_irq(pdev, 0);
>
> base-commit: 7d2a07b769330c34b4deabeed939325c77a7ec2f
> --
> 2.30.2
>
>
>
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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