From: wangzhou1@hisilicon•com (Zhou Wang)
To: linux-arm-kernel@lists•infradead.org
Subject: [Question] PCI ACS is broken for ARM SMMU v3?
Date: Mon, 4 Sep 2017 20:33:22 +0800 [thread overview]
Message-ID: <59AD4812.3020602@hisilicon.com> (raw)
In-Reply-To: <59A81B4C.3020402@hisilicon.com>
+to: Lorenzo
On 2017/8/31 22:21, Zhou Wang wrote:
> Hi Will and Alex,
>
> pci_request_acs is called in drivers/iommu/arm-smmu-v3.c to set pci_acs_enable.
>
> PCI subsystem tries to enable ACS as below:
>
> pci_device_add
> --> pci_init_capabilities
> --> pci_enable_acs
>
> in ACPI PCI driver. However, ACPI PCI driver will be called before SMMU v3 driver,
> which will lead pci_enable_acs to return directly as pci_acs_enable is not set
> before SMMU v3 driver loading.
>
> I think this is a bug, what do you think about this problem?
>
> Best,
> Zhou
>
>
>
>
>
> .
>
next prev parent reply other threads:[~2017-09-04 12:33 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-31 14:21 [Question] PCI ACS is broken for ARM SMMU v3? Zhou Wang
2017-09-04 12:33 ` Zhou Wang [this message]
2017-09-04 15:59 ` Lorenzo Pieralisi
2017-09-05 12:47 ` Zhou Wang
2017-09-06 9:55 ` Lorenzo Pieralisi
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