Todd,
[...]
> > + /* Initialize the gpio bank registers to init time value */
> > + omap_gpio_mod_init(bank);
>
> omap_gpio_mod_init calls mpuio_init calls platform_driver_register
> which can't be called in an IRQs off and spinlocked atomic context,
> for example, device_private_init calls kzalloc with GFP_KERNEL.
>
> Concurrency protection for this will need to happen prior to the
> spinlock (assuming it really does need to be an IRQ saving spinlock
> and not a mutex). Possibly a new mutex is needed to protect the
> check for first usage and init'ing the bank (and blocking a racing
> second caller until the init is done).
I have isolated mpuio_init() from omap_gpio_mod_init().
mpuio_init() is now called once in omap_gpio_probe().
>
> The omap_gpio_mod_init may be unbalanced with the code performed below
> on last free of a GPIO for the bank? If all GPIOs are freed and then
> a new GPIO used, does omap_gpio_mod_init do the right thing? Need a
> separate flag to indicate whether one-time init has ever been
> performed, vs. needing runtime PM enable/disable?
With the above changes I am seeing omap_gpio_mod_init() is balanced.
Let me know if I am still missing something.
--
Tarun
>
> > + }
> > +
> > /* Set trigger to none. You need to enable the desired trigger with
> > * request_irq() or set_irq_type().
> > */
> > @@ -517,7 +535,6 @@ static void omap_gpio_free(struct gpio_chip *chip,
> unsigned offset)
> > unsigned long flags;
> >
> > spin_lock_irqsave(&bank->lock, flags);
> > -
> > if (bank->regs->wkup_status)
> > /* Disable wake-up during idle for dynamic tick */
> > _gpio_rmw(base, bank->regs->wkup_status, 1 << offset, 0);
> > @@ -535,6 +552,18 @@ static void omap_gpio_free(struct gpio_chip *chip,
> unsigned offset)
> > }
> >
> > _reset_gpio(bank, bank->chip.base + offset);
> > +
> > + /*
> > + * If this is the last gpio to be freed in the bank,
> > + * disable the bank module.
> > + */
> > + if (!bank->mod_usage) {
> > + if (IS_ERR_VALUE(pm_runtime_put_sync(bank->dev) < 0)) {
> > + dev_err(bank->dev, "%s: GPIO bank %d "
> > + "pm_runtime_put_sync failed\n",
> > + __func__, bank->id);
> > + }
> > + }
> > spin_unlock_irqrestore(&bank->lock, flags);
>
>
> Todd
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