Re: [PATCH] pinctrl: baytrail: Do not clear IRQ flags on direct-irq enabled pins

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

On Sat, Dec 28, 2019 at 12:04:47AM +0100, Hans de Goede wrote:
> Suspending Goodix touchscreens requires changing the interrupt pin to
> output before sending them a power-down command. Followed by wiggling
> the interrupt pin to wake the device up, after which it is put back
> in input mode.
> 
> On Bay Trail devices with a Goodix touchscreen direct-irq mode is used
> in combination with listing the pin as a normal GpioIo resource.
> 
> This works fine, until the goodix driver gets rmmod-ed and then insmod-ed
> again. In this case byt_gpio_disable_free() calls
> byt_gpio_clear_triggering() which clears the IRQ flags and after that the
> (direct) IRQ no longer triggers.
> 
> This commit fixes this by adding a check for the BYT_DIRECT_IRQ_EN flag
> to byt_gpio_clear_triggering().
> 
> Note that byt_gpio_clear_triggering() only gets called from
> byt_gpio_disable_free() for direct-irq enabled pins, as these are excluded
> from the irq_valid mask by byt_init_irq_valid_mask().
> 

Pushed to my review and testing queue, thanks!

> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
>  drivers/pinctrl/intel/pinctrl-baytrail.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/pinctrl/intel/pinctrl-baytrail.c b/drivers/pinctrl/intel/pinctrl-baytrail.c
> index db55761c90cc..844b89f230d7 100644
> --- a/drivers/pinctrl/intel/pinctrl-baytrail.c
> +++ b/drivers/pinctrl/intel/pinctrl-baytrail.c
> @@ -742,8 +742,13 @@ static void byt_gpio_clear_triggering(struct intel_pinctrl *vg, unsigned int off
>  
>  	raw_spin_lock_irqsave(&byt_lock, flags);
>  	value = readl(reg);
> +	/* Do not clear direct-irq enabled irqs (from gpio_disable_free) */
> +	if (value & BYT_DIRECT_IRQ_EN)
> +		goto out;
> +
>  	value &= ~(BYT_TRIG_POS | BYT_TRIG_NEG | BYT_TRIG_LVL);
>  	writel(value, reg);
> +out:
>  	raw_spin_unlock_irqrestore(&byt_lock, flags);
>  }
>  
> -- 
> 2.24.1
> 

-- 
With Best Regards,
Andy Shevchenko