> -----Original Message-----
> From: Todd Poynor [mailto:toddpoy...@google.com]
> Sent: Thursday, July 14, 2011 11:40 AM
> To: DebBarma, Tarun Kanti
> Cc: linux-omap@vger.kernel.org; Hilman, Kevin; Shilimkar, Santosh;
> t...@atomide.com; linux-arm-ker...@lists.infradead.org; Varadarajan,
> Charulatha
> Subject: Re: [PATCH v4 18/20] gpio/omap: use pm-runtime framework
>
> On Wed, Jul 13, 2011 at 07:24:17PM +0530, Tarun Kanti DebBarma wrote:
> > From: Charulatha V <ch...@ti.com>
> >
> > Call runtime pm APIs pm_runtime_get_sync() and pm_runtime_put_sync()
> > for enabling/disabling clocks appropriately. Remove syscore_ops and
> > instead use dev_pm_ops now.
> >
> ...
> > + /*
> > + * If this is the first gpio_request for the bank,
> > + * enable the bank module.
> > + */
> > + if (!bank->mod_usage) {
> > + if (IS_ERR_VALUE(pm_runtime_get_sync(bank->dev) < 0)) {
> > + dev_err(bank->dev, "%s: GPIO bank %d "
> > + "pm_runtime_get_sync failed\n",
> > + __func__, bank->id);
> > + return -EINVAL;
> > + }
> > +
> > + /* Initialize the gpio bank registers to init time value */
> > + omap_gpio_mod_init(bank);
> > + }
> > +
> > spin_lock_irqsave(&bank->lock, flags);
>
> Does the check for first gpio_request and omap_gpio_mod_init() call
> need concurrency protection, possibly moved under the spinlock?
I believe, with pm_runtime_irq_safe() already in place, we could move
them including *_get_sync() under spinlock.
>
> >
> > /* Set trigger to none. You need to enable the desired trigger with
> > @@ -536,6 +554,18 @@ static void omap_gpio_free(struct gpio_chip *chip,
> unsigned offset)
> >
> > _reset_gpio(bank, bank->chip.base + offset);
> > spin_unlock_irqrestore(&bank->lock, flags);
> > +
> > + /*
> > + * 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);
> > + }
> > + }
>
> And need mutual exclusion here?
Yes.
I will verify and take action. Thanks.
--
Tarun
>
>
> Todd
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