Messages in this thread | | | From | "Lad, Prabhakar" <> | Date | Thu, 9 Dec 2021 11:34:31 +0000 | Subject | Re: [RFC PATCH] of: platform: Skip mapping of interrupts in of_device_alloc() |
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Hi Rob and Marc,
On Thu, Dec 9, 2021 at 10:33 AM Marc Zyngier <maz@kernel.org> wrote: > > On Thu, 09 Dec 2021 10:00:44 +0000, > "Lad, Prabhakar" <prabhakar.csengg@gmail.com> wrote: > > > > > The root of the issue is that all the resource allocation is done > > > upfront, way before we even have a driver that could potentially > > > deal with this device. This is a potential waste of resource, and > > > it triggers the issue you noticed. > > > > > > If you delay the resource allocation until there is an actual > > > match with a driver, you could have a per-driver flag telling you > > > whether the IRQ allocation should be performed before the probe() > > > function is called. > > > > > As suggested by Rob, if we switch the drivers to use > > platform_get_resource(pdev, IORESOURCE_IRQ, n) call with > > platform_get_irq() this code should go away and with this switch the > > resource allocation will happen demand. Is this approach OK? > > If you get rid of of_irq_to_resource_table() altogether, then yes, > this has a fighting chance to work. > Yes, switching to platform_get_irq() will eventually cause of_irq_to_resource_table() to go away.
On second thought, instead of touching all the drivers, if we update platform_get_resource/platform_get_resource_byname to internally call platform_get_irq() internally if it's a IORESOURCE_IRQ resource. Does that sound good or should I just get on changing all the drivers to use platform_get_irq() instead?
Cheers, Prabhakar
> M. > > > -- > Without deviation from the norm, progress is not possible.
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