[alsa-devel] [PATCH] Allow passing platform_data to devices attached to AC97 bus
marek.vasut at gmail.com
Wed Jul 22 00:40:56 CEST 2009
Dne St 22. července 2009 00:39:00 Marek Vasut napsal(a):
> Dne St 22. července 2009 00:33:34 Russell King - ARM Linux napsal(a):
> > On Wed, Jul 22, 2009 at 12:13:12AM +0200, Marek Vasut wrote:
> > > + ret = set_irq_type(gpio_to_irq(pdata->charge_gpio),
> > > + IRQ_TYPE_EDGE_BOTH);
> > > + if (ret)
> > > + goto err2;
> > > + ret = request_irq(gpio_to_irq(pdata->charge_gpio),
> > > + wm97xx_chrg_irq, IRQF_DISABLED,
> > > + "AC Detect", 0);
> > This should be done as one call to request_irq().
> > Why?
> > If the IRQ is already in use by something else, calling set_irq_type()
> > will stamp on that other user, enforcing the change of configuration.
> > request_irq() will then fail, leaving the IRQ configuration buggered.
> > Combining the two allows request_irq() to fail if the IRQ line is busy.
> > If it isn't busy, it will configure the IRQ line prior to enabling the
> > IRQ. If the IRQ is shared and sharing is permitted, it will fail if
> > the configuration is not compatible with the existing IRQ configuration.
> > set_irq_type() should only be used very sparingly and when there's no
> > other option.
> Sorry, I removed that, this patch should be OK.
Argh, I forget to fix the goto label.
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