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From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 3/7] iommu/arm-smmu-v3: Introduce smmu option USE_SHARED_IRQS for Silicon errata
Date: Tue, 11 Apr 2017 17:21:24 +0100	[thread overview]
Message-ID: <20170411162123.GF17109@arm.com> (raw)
In-Reply-To: <b84e2383-1a65-3c5a-8e2c-28eafdb20adc@arm.com>

On Tue, Apr 11, 2017 at 04:54:26PM +0100, Robin Murphy wrote:
> On 11/04/17 15:42, linucherian at gmail.com wrote:
> > From: Geetha <gakula@cavium.com>
> > 
> > Cavium 99xx SMMU implementation doesn't not support unique irq lines for
> > gerror, eventq and cmdq-sync. USE_SHARED_IRQS option enables to use single
> > irq line for all three interrupts.
> 
> AFAICS, there's nothing actually wrong with using shared wired IRQs -
> the architecture spec doesn't appear to say anything about it. I think
> it might suffice to simply add IRQF_SHARED if we can see the SMMU
> doesn't support MSIs anyway - it doesn't really seem like something we
> need to treat as a specific quirk.

No, this is not permitted by the spec. See 3.18.2 ("Interrupt sources"),
where it's clear that each source asserts a *unique* wired interrupt.

Geetha: does your implementation support MSIs?

Will

  reply	other threads:[~2017-04-11 16:21 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-11 14:42 [RFC PATCH 0/7] Cavium CN99xx SMMUv3 Errata workarounds linucherian at gmail.com
2017-04-11 14:42 ` [RFC PATCH 1/7] iommu/arm-smmu-v3: Introduce smmu option PAGE0_REGS_ONLY for Silicon errata linucherian at gmail.com
2017-04-11 15:42   ` Robin Murphy
2017-04-12  5:05     ` Linu Cherian
2017-04-11 14:42 ` [RFC PATCH 2/7] iommu/arm-smmu-v3: Do resource size checks based on smmu option PAGE0_REGS_ONLY linucherian at gmail.com
2017-04-11 15:43   ` Robin Murphy
2017-04-11 16:39     ` Sunil Kovvuri
2017-04-11 14:42 ` [RFC PATCH 3/7] iommu/arm-smmu-v3: Introduce smmu option USE_SHARED_IRQS for Silicon errata linucherian at gmail.com
2017-04-11 15:54   ` Robin Murphy
2017-04-11 16:21     ` Will Deacon [this message]
2017-04-11 16:34       ` Sunil Kovvuri
2017-04-11 16:38       ` Robin Murphy
2017-04-11 16:41         ` Will Deacon
2017-04-11 14:42 ` [RFC PATCH 4/7] ACPICA: IORT: Add SMMuV3 model definitions linucherian at gmail.com
2017-04-11 15:59   ` Robin Murphy
2017-04-11 16:57     ` Sunil Kovvuri
2017-04-12  2:33       ` Hanjun Guo
2017-04-12 15:21       ` Lorenzo Pieralisi
2017-04-11 14:42 ` [RFC PATCH 5/7] iommu/arm-smmu-v3: For ACPI based device probing, set relevant options for different SMMUv3 implementations linucherian at gmail.com
2017-04-12  8:43   ` Robert Richter
2017-04-12 10:32     ` Linu Cherian
2017-04-11 14:42 ` [RFC PATCH 6/7] ACPI/IORT: Fixup SMMUv3 resource size for Cavium 99xx SMMUv3 model linucherian at gmail.com
2017-04-11 14:42 ` [RFC PATCH 7/7] arm64: Documentation: Add Cavium ThunderX2 SMMUv3 erratas linucherian at gmail.com
2017-04-11 16:30 ` [RFC PATCH 0/7] Cavium CN99xx SMMUv3 Errata workarounds Will Deacon

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