Re: [GIT pull] irq updates for 4.13

[Sebastian Reichel]

Hi,

On Tue, Jul 11, 2017 at 06:51:32AM -0700, Tony Lindgren wrote:
> * Thomas Gleixner <tglx@xxxxxxxxxxxxx> [170711 02:48]:
> > On Tue, 11 Jul 2017, Thomas Gleixner wrote:
> > 
> > So Tony actually provided the part of dmesg which shows the initial
> > failure, which subsequently leads to the splat Sebastian reported.
> > 
> > Unhandled fault: external abort on non-linefetch (0x1028) at 0xfb050034
> > pgd = c0004000 [fb050034] *pgd=49011452(bad)
> > Internal error: : 1028 [#1] SMP ARM
> > Workqueue: events deferred_probe_work_func
> > task: ce1d41c0 task.stack: ce1fc000
> > PC is at omap_gpio_get_direction+0x2c/0x44
> > LR is at _raw_spin_lock_irqsave+0x40/0x4c
> > pc : [<c0509258>]    lr : [<c08263c4>]    psr: 60000093
> > sp : ce1fdb78  ip : c0dce42c  fp : ce22d810
> > r10: ce22d800  r9 : 00000000  r8 : ce22d900
> > r7 : 00000016  r6 : ce223864  r5 : fb050034  r4 : 00000020
> > r3 : ce1d41c0  r2 : 00000000  r1 : a0000013  r0 : a0000013
> > Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment none
> > Control: 10c5387d  Table: 80004019  DAC: 00000051
> > Process kworker/0:1 (pid: 14, stack limit = 0xce1fc218)
> > 
> > The callstack is:
> > 
> > omap_gpio_get_direction
> > gpiochip_lock_as_irq
> > gpiochip_irq_reqres
> > __setup_irq
> > request_threaded_irq
> > smc_probe
> > smc_drv_probe
> > platform_drv_probe
> > ....
> > 
> > So the SMC91X network driver request an IRQ, which ends up calling into the
> > GPIO interrupt setup and that fails. I have no idea why that would not fail
> > with the patch reverted. Dusting off a Beaglebone board....
> 
> And "external abort on non-linefetch" means something is not clocked
> in this case. The following alone makes things boot for me again, but I don't
> quite follow what has now changed with the ordering.. Thomas, any ideas?
> 
> Anyways, adding Linus W and Grygorii to Cc since things now point to
> gpio-omap.
> 
> Regards,
> 
> Tony

Ack, that also works for me. The strange thing is, that I added the
following before and it did not print anything.

if (!pm_runtime_enabled(bank->chip.parent))
    dev_err(bank->chip.parent, "runtime pm issue!\n");

-- Sebastian

> 8< ---------------------
> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
> --- a/drivers/gpio/gpio-omap.c
> +++ b/drivers/gpio/gpio-omap.c
> @@ -919,13 +919,24 @@ static int omap_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
>  	struct gpio_bank *bank;
>  	unsigned long flags;
>  	void __iomem *reg;
> -	int dir;
> +	int error, dir;
>  
>  	bank = gpiochip_get_data(chip);
>  	reg = bank->base + bank->regs->direction;
> +	error = pm_runtime_get_sync(bank->chip.parent);
> +	if (error < 0) {
> +		dev_err(bank->chip.parent,
> +			"Could not enable gpio bank %p: %d\n",
> +			bank, error);
> +		pm_runtime_put_noidle(bank->chip.parent);
> +
> +		return error;
> +	}
>  	raw_spin_lock_irqsave(&bank->lock, flags);
>  	dir = !!(readl_relaxed(reg) & BIT(offset));
>  	raw_spin_unlock_irqrestore(&bank->lock, flags);
> +	pm_runtime_put_sync(bank->chip.parent);
> +
>  	return dir;
>  }
>  
> -- 
> 2.13.2

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