From: Joerg Roedel <joro@8bytes.org>
To: Baoquan He <bhe@redhat.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: A question about state machine function state_next()
Date: Mon, 1 Jun 2015 14:01:03 +0200 [thread overview]
Message-ID: <20150601120103.GF20384@8bytes.org> (raw)
In-Reply-To: <20150601111802.GD31271@dhcp-128-28.nay.redhat.com>
On Mon, Jun 01, 2015 at 07:18:02PM +0800, Baoquan He wrote:
> Checked the code again, it may be a code bug if this is done in
> device_dma_ops_init(). Since this is called in
> amd_iommu_init_dma_ops()<-amd_iommu_init_dma(). And amd_iommu_init_dma()
> is only called in case IOMMU_INTERRUPTS_EN code block. According to the
> code flow if I understand correctly, it can't be here at boot stage.
> state_next() will change the state according to the calling times. And
> in amd iommu only four times to call iommu_go_to_state, it can't go to
> IOMMU_PCI_INIT and the after cases.
>
> I am not sure if my understanding is correct, or I missed something.
You probably missed the loop in iommu_go_to_state() which will call
state_next() until it reaches either the requested state or an error
state.
Joerg
next prev parent reply other threads:[~2015-06-01 12:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-01 3:09 A question about state machine function state_next() Baoquan He
2015-06-01 6:42 ` Joerg Roedel
2015-06-01 9:09 ` Baoquan He
2015-06-01 9:21 ` Joerg Roedel
2015-06-01 10:19 ` Baoquan He
2015-06-01 10:33 ` Joerg Roedel
2015-06-01 11:11 ` Baoquan He
2015-06-01 11:18 ` Baoquan He
2015-06-01 12:01 ` Joerg Roedel [this message]
2015-06-01 14:01 ` Baoquan He
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