Re: [PATCH] pinctrl: cherryview: fix issues caused by dynamic gpio irqs mapping

[Andy Shevchenko <andy.shevchenko@xxxxxxxxx>]

On Tue, Oct 3, 2017 at 8:00 PM, Grygorii Strashko
<grygorii.strashko@xxxxxx> wrote:
> New GPIO IRQs are allocated and mapped dynamically by default when
> GPIO IRQ infrastructure is used by cherryview-pinctrl driver.
> This causes issues on some Intel platforms [1][2] with broken BIOS which
> hardcodes Linux IRQ numbers in their ACPI tables.
>
> On such platforms cherryview-pinctrl driver should allocate and map all
> GPIO IRQs at probe time.
> Side effect - "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n"
> can be seen at boot log.
>
> NOTE. It still may fail if boot sequence will changed and some interrupt
> controller will be probed before cherryview-pinctrl which will shift Linux IRQ
> numbering (expected with CONFIG_SPARCE_IRQ enabled).
>
> [1] https://bugzilla.kernel.org/show_bug.cgi?id=194945
> [2] https://lkml.org/lkml/2017/9/28/153

Btw, you might want to use one of

Buglink:
Bugzilla:
Link:

tags.

> Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Cc: Chris Gorman <chrisjohgorman@xxxxxxxxx>
> Cc: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Cc: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
> Reported-by: Chris Gorman <chrisjohgorman@xxxxxxxxx>
> Reported-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>

I'm not sure about this approach. It might be some other broken BIOS
discovered with some other driver (like pinctrl-baytrail.c as an
hypothetical example).

Alternative is to deselect SPARSE_IRQ (though it makes it non-usable
in entire x86 world).

>  drivers/pinctrl/intel/pinctrl-cherryview.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pinctrl/intel/pinctrl-cherryview.c b/drivers/pinctrl/intel/pinctrl-cherryview.c
> index 04e929f..fadbca9 100644
> --- a/drivers/pinctrl/intel/pinctrl-cherryview.c
> +++ b/drivers/pinctrl/intel/pinctrl-cherryview.c
> @@ -1577,6 +1577,7 @@ static int chv_gpio_probe(struct chv_pinctrl *pctrl, int irq)
>         struct gpio_chip *chip = &pctrl->chip;
>         bool need_valid_mask = !dmi_check_system(chv_no_valid_mask);
>         int ret, i, offset;
> +       int irq_base;
>
>         *chip = chv_gpio_chip;
>
> @@ -1622,7 +1623,18 @@ static int chv_gpio_probe(struct chv_pinctrl *pctrl, int irq)
>         /* Clear all interrupts */
>         chv_writel(0xffff, pctrl->regs + CHV_INTSTAT);
>
> -       ret = gpiochip_irqchip_add(chip, &chv_gpio_irqchip, 0,
> +       if (!need_valid_mask) {
> +               irq_base = devm_irq_alloc_descs(pctrl->dev, -1, 0,
> +                                               chip->ngpio, NUMA_NO_NODE);
> +               if (irq_base < 0) {
> +                       dev_err(pctrl->dev, "Failed to allocate IRQ numbers\n");
> +                       return irq_base;
> +               }
> +       } else {
> +               irq_base = 0;
> +       }
> +
> +       ret = gpiochip_irqchip_add(chip, &chv_gpio_irqchip, irq_base,
>                                    handle_bad_irq, IRQ_TYPE_NONE);
>         if (ret) {
>                 dev_err(pctrl->dev, "failed to add IRQ chip\n");
> --
> 2.10.1
>



-- 
With Best Regards,
Andy Shevchenko
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