From: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
To: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Subject: Re: [PATCH] iommu/arm-smmu-v3: Warn about missing IRQs
Date: Fri, 27 Oct 2017 17:52:16 +0100 [thread overview]
Message-ID: <20171027165215.GA28642@arm.com> (raw)
In-Reply-To: <f03a7c9f0be2f0af461b61d18fff3c931da77ebb.1509109598.git.robin.murphy-5wv7dgnIgG8@public.gmane.org>
On Fri, Oct 27, 2017 at 02:08:16PM +0100, Robin Murphy wrote:
> It is annoyingly non-obvious when DMA transactions silently go missing
> due to undetected SMMU faults. Help skip the first few debugging steps
> in those situations by making it clear when we have neither wired IRQs
> nor MSIs with which to raise error conditions.
>
> Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
> ---
> drivers/iommu/arm-smmu-v3.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index e67ba6c40faf..1a374c5c9507 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -2263,6 +2263,8 @@ static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
> "arm-smmu-v3-evtq", smmu);
> if (ret < 0)
> dev_warn(smmu->dev, "failed to enable evtq irq\n");
> + } else {
> + dev_warn(smmu->dev, "no evtq irq - events will not be reported!\n");
> }
>
> irq = smmu->cmdq.q.irq;
> @@ -2280,6 +2282,8 @@ static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
> 0, "arm-smmu-v3-gerror", smmu);
> if (ret < 0)
> dev_warn(smmu->dev, "failed to enable gerror irq\n");
> + } else {
> + dev_warn(smmu->dev, "no gerr irq - errors will not be reported!\n");
> }
>
> if (smmu->features & ARM_SMMU_FEAT_PRI) {
Can we also print something similar for the PRIQ when we detect that PRI is
supported, please? Whilst I agree that event and gerror are the critical
ones, I'm not sure how a PCIe device behaves if its PRI requests are
ignored, but this might help to debug it.
Will
WARNING: multiple messages have this Message-ID (diff)
From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] iommu/arm-smmu-v3: Warn about missing IRQs
Date: Fri, 27 Oct 2017 17:52:16 +0100 [thread overview]
Message-ID: <20171027165215.GA28642@arm.com> (raw)
In-Reply-To: <f03a7c9f0be2f0af461b61d18fff3c931da77ebb.1509109598.git.robin.murphy@arm.com>
On Fri, Oct 27, 2017 at 02:08:16PM +0100, Robin Murphy wrote:
> It is annoyingly non-obvious when DMA transactions silently go missing
> due to undetected SMMU faults. Help skip the first few debugging steps
> in those situations by making it clear when we have neither wired IRQs
> nor MSIs with which to raise error conditions.
>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
> drivers/iommu/arm-smmu-v3.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index e67ba6c40faf..1a374c5c9507 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -2263,6 +2263,8 @@ static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
> "arm-smmu-v3-evtq", smmu);
> if (ret < 0)
> dev_warn(smmu->dev, "failed to enable evtq irq\n");
> + } else {
> + dev_warn(smmu->dev, "no evtq irq - events will not be reported!\n");
> }
>
> irq = smmu->cmdq.q.irq;
> @@ -2280,6 +2282,8 @@ static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
> 0, "arm-smmu-v3-gerror", smmu);
> if (ret < 0)
> dev_warn(smmu->dev, "failed to enable gerror irq\n");
> + } else {
> + dev_warn(smmu->dev, "no gerr irq - errors will not be reported!\n");
> }
>
> if (smmu->features & ARM_SMMU_FEAT_PRI) {
Can we also print something similar for the PRIQ when we detect that PRI is
supported, please? Whilst I agree that event and gerror are the critical
ones, I'm not sure how a PCIe device behaves if its PRI requests are
ignored, but this might help to debug it.
Will
next prev parent reply other threads:[~2017-10-27 16:52 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-27 13:08 [PATCH] iommu/arm-smmu-v3: Warn about missing IRQs Robin Murphy
2017-10-27 13:08 ` Robin Murphy
[not found] ` <f03a7c9f0be2f0af461b61d18fff3c931da77ebb.1509109598.git.robin.murphy-5wv7dgnIgG8@public.gmane.org>
2017-10-27 16:52 ` Will Deacon [this message]
2017-10-27 16:52 ` Will Deacon
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