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Groups > linux.kernel > #1627247
| From | Marc Zyngier <marc.zyngier@arm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [RFC PATCH v0.2] PCI: Add support for tango PCIe host bridge |
| Date | 2017-04-20 11:50 +0200 |
| Message-ID | <tygSS-7gN-19@gated-at.bofh.it> (permalink) |
| References | (11 earlier) <tvlvI-24R-15@gated-at.bofh.it> <tvnea-2SU-9@gated-at.bofh.it> <tvnea-2SU-7@gated-at.bofh.it> <txVY5-2QX-7@gated-at.bofh.it> <tyfDs-6zX-7@gated-at.bofh.it> |
| Organization | ARM Ltd |
On 20/04/17 09:20, Mason wrote:
> On 19/04/2017 13:19, Mason wrote:
>
>> My biggest problem is that tango_unmask() is never called.
>
> FTR, the missing incantation was:
> Explicitly calling tango_{mask/unmask/ack} from the corresponding msi_{mask/unmask/ack}
Using irq_chip_mask_parent and co, you mean?
> Marc, I have one nagging doubt, wrt splitting MSI line selection
> and MSI enable.
>
> tango_irq_domain_alloc : finds an available MSI 'j' to allocate
> tango_irq_domain_free : release MSI 'j'
> tango_unmask : enable MSI 'j'
> tango_mask : disable MSI 'j'
>
> Is the following scenario guaranteed to never happen?
>
> tango_irq_domain_alloc // alloc 0
> tango_irq_domain_free // free 0
> tango_irq_domain_alloc // alloc 0
> tango_unmask // enable 0
> tango_unmask // enable 0 = NOP
> tango_mask // disable 0
>
> In this theoretical scenario, we would be left with a non-functional
> MSI 0.
I'm not sure I get the example above, and what the various alloc/free
calls have to do with anything. If you have unbalanced
enable/disable_irq, you loose. Don't do that.
M.
--
Jazz is not dead. It just smells funny...
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Re: [RFC PATCH v0.2] PCI: Add support for tango PCIe host bridge Mason <slash.tmp@free.fr> - 2017-04-11 17:20 +0200
Re: [RFC PATCH v0.2] PCI: Add support for tango PCIe host bridge Marc Zyngier <marc.zyngier@arm.com> - 2017-04-11 18:00 +0200
Re: [RFC PATCH v0.2] PCI: Add support for tango PCIe host bridge Mason <slash.tmp@free.fr> - 2017-04-11 18:30 +0200
Re: [RFC PATCH v0.2] PCI: Add support for tango PCIe host bridge Marc Zyngier <marc.zyngier@arm.com> - 2017-04-11 18:50 +0200
Re: [RFC PATCH v0.2] PCI: Add support for tango PCIe host bridge Mason <slash.tmp@free.fr> - 2017-04-11 20:00 +0200
Re: [RFC PATCH v0.2] PCI: Add support for tango PCIe host bridge Marc Zyngier <marc.zyngier@arm.com> - 2017-04-12 10:10 +0200
Re: [RFC PATCH v0.2] PCI: Add support for tango PCIe host bridge Marc Zyngier <marc.zyngier@arm.com> - 2017-04-12 12:00 +0200
Re: [RFC PATCH v0.2] PCI: Add support for tango PCIe host bridge Mason <slash.tmp@free.fr> - 2017-04-19 13:30 +0200
Re: [RFC PATCH v0.2] PCI: Add support for tango PCIe host bridge Mason <slash.tmp@free.fr> - 2017-04-20 10:30 +0200
Re: [RFC PATCH v0.2] PCI: Add support for tango PCIe host bridge Marc Zyngier <marc.zyngier@arm.com> - 2017-04-20 11:50 +0200
Re: [RFC PATCH v0.2] PCI: Add support for tango PCIe host bridge Mason <slash.tmp@free.fr> - 2017-04-12 12:00 +0200
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