Re: [RFC PATCH 4/4] pinctrl: rockchip: avoid hardirq-unsafe functions in irq_chip

Heiko Stuebner
2017-03-15T17:04:37Z

Am Montag, 13. März 2017, 18:38:13 CET schrieb John Keeping:
> With real-time preemption, regmap functions cannot be used in the
> implementation of irq_chip since they use spinlocks which may sleep.
>
> Move the setting of the mux for IRQs to an irq_bus_sync_unlock handler
> where we are allowed to sleep.
>
> Signed-off-by: John Keeping <john-HooS5bfzL4hWk0Htik3J/w@public.gmane.org>

Looks good
Reviewed-by: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>

> ---
> drivers/pinctrl/pinctrl-rockchip.c | 44
> ++++++++++++++++++++++++++++++++++---- 1 file changed, 40 insertions(+), 4
> deletions(-)
>
> diff --git a/drivers/pinctrl/pinctrl-rockchip.c
> b/drivers/pinctrl/pinctrl-rockchip.c index 52e70c4aef7c..80f7c23d12d4
> 100644
> --- a/drivers/pinctrl/pinctrl-rockchip.c
> +++ b/drivers/pinctrl/pinctrl-rockchip.c
> @@ -143,6 +143,9 @@ struct rockchip_drv {
> * @gpio_chip: gpiolib chip
> * @grange: gpio range
> * @slock: spinlock for the gpio bank
> + * @irq_lock: bus lock for irq chip
> + * @new_irqs: newly configured irqs which must be muxed as GPIOs in
> + * irq_bus_sync_unlock()
> */
> struct rockchip_pin_bank {
> void __iomem *reg_base;
> @@ -165,6 +168,8 @@ struct rockchip_pin_bank {
> struct pinctrl_gpio_range grange;
> raw_spinlock_t slock;
> u32 toggle_edge_mode;
> + struct mutex irq_lock;
> + u32 new_irqs;
> };
>
> #define PIN_BANK(id, pins, label) \
> @@ -2045,11 +2050,12 @@ static int rockchip_irq_set_type(struct irq_data *d,
> unsigned int type) int ret;
>
> /* make sure the pin is configured as gpio input */
> - ret = rockchip_set_mux(bank, d->hwirq, RK_FUNC_GPIO);
> + ret = rockchip_verify_mux(bank, d->hwirq, RK_FUNC_GPIO);
> if (ret < 0)
> return ret;
>
> - clk_enable(bank->clk);
> + bank->new_irqs |= mask;
> +
> raw_spin_lock_irqsave(&bank->slock, flags);
>
> data = readl_relaxed(bank->reg_base + GPIO_SWPORT_DDR);
> @@ -2107,7 +2113,6 @@ static int rockchip_irq_set_type(struct irq_data *d,
> unsigned int type) default:
> irq_gc_unlock(gc);
> raw_spin_unlock_irqrestore(&bank->slock, flags);
> - clk_disable(bank->clk);
> return -EINVAL;
> }
>
> @@ -2116,7 +2121,6 @@ static int rockchip_irq_set_type(struct irq_data *d,
> unsigned int type)
>
> irq_gc_unlock(gc);
> raw_spin_unlock_irqrestore(&bank->slock, flags);
> - clk_disable(bank->clk);
>
> return 0;
> }
> @@ -2160,6 +2164,34 @@ static void rockchip_irq_gc_mask_set_bit(struct
> irq_data *d) clk_disable(bank->clk);
> }
>
> +static void rockchip_irq_bus_lock(struct irq_data *d)
> +{
> + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> + struct rockchip_pin_bank *bank = gc->private;
> +
> + clk_enable(bank->clk);
> + mutex_lock(&bank->irq_lock);
> +}
> +
> +static void rockchip_irq_bus_sync_unlock(struct irq_data *d)
> +{
> + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> + struct rockchip_pin_bank *bank = gc->private;
> +
> + while (bank->new_irqs) {
> + unsigned int irq = __ffs(bank->new_irqs);
> + int ret;
> +
> + ret = rockchip_set_mux(bank, irq, RK_FUNC_GPIO);
> + WARN_ON(ret < 0);
> +
> + bank->new_irqs &= ~BIT(irq);
> + }
> +
> + mutex_unlock(&bank->irq_lock);
> + clk_disable(bank->clk);
> +}
> +
> static int rockchip_interrupts_register(struct platform_device *pdev,
> struct rockchip_pinctrl *info)
> {
> @@ -2225,6 +2257,9 @@ static int rockchip_interrupts_register(struct
> platform_device *pdev, gc->chip_types[0].chip.irq_suspend =
> rockchip_irq_suspend;
> gc->chip_types[0].chip.irq_resume = rockchip_irq_resume;
> gc->chip_types[0].chip.irq_set_type = rockchip_irq_set_type;
> + gc->chip_types[0].chip.irq_bus_lock = rockchip_irq_bus_lock;
> + gc->chip_types[0].chip.irq_bus_sync_unlock =
> + rockchip_irq_bus_sync_unlock;
> gc->wake_enabled = IRQ_MSK(bank->nr_pins);
>
> irq_set_chained_handler_and_data(bank->irq,
> @@ -2398,6 +2433,7 @@ static struct rockchip_pin_ctrl
> *rockchip_pinctrl_get_soc_data( int bank_pins = 0;
>
> raw_spin_lock_init(&bank->slock);
> + mutex_init(&bank->irq_lock);
> bank->drvdata = d;
> bank->pin_base = ctrl->nr_pins;
> ctrl->nr_pins += bank->nr_pins;