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iommu/rockchip: Move irq request past pm_runtime_enable

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[ Upstream commit 1aa55ca9b14af6cfd987ce4fdaf548f7067a5d07 ]

Enabling the interrupt early, before power has been applied to the
device, can result in an interrupt being delivered too early if:

- the IOMMU shares an interrupt with a VOP
- the VOP has a pending interrupt (after a kexec, for example)

In these conditions, we end-up taking the interrupt without
the IOMMU being ready to handle the interrupt (not powered on).

Moving the interrupt request past the pm_runtime_enable() call
makes sure we can at least access the IOMMU registers. Note that
this is only a partial fix, and that the VOP interrupt will still
be screaming until the VOP driver kicks in, which advocates for
a more synchronized interrupt enabling/disabling approach.

Fixes: 0f181d3cf7d98 ("iommu/rockchip: Add runtime PM support")
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Marc Zyngier 2018-08-24 16:06:37 +01:00 committed by Greg Kroah-Hartman
parent d30de7347e
commit 69177abd89
1 changed files with 13 additions and 11 deletions
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24
drivers/iommu/rockchip-iommu.c
View File

@ -1161,17 +1161,6 @@ static int rk_iommu_probe(struct platform_device *pdev)
if (iommu->num_mmu == 0)
return PTR_ERR(iommu->bases[0]);
i = 0;
while ((irq = platform_get_irq(pdev, i++)) != -ENXIO) {
if (irq < 0)
return irq;
err = devm_request_irq(iommu->dev, irq, rk_iommu_irq,
IRQF_SHARED, dev_name(dev), iommu);
if (err)
return err;
}
iommu->reset_disabled = device_property_read_bool(dev,
"rockchip,disable-mmu-reset");
@ -1228,6 +1217,19 @@ static int rk_iommu_probe(struct platform_device *pdev)
pm_runtime_enable(dev);
i = 0;
while ((irq = platform_get_irq(pdev, i++)) != -ENXIO) {
if (irq < 0)
return irq;
err = devm_request_irq(iommu->dev, irq, rk_iommu_irq,
IRQF_SHARED, dev_name(dev), iommu);
if (err) {
pm_runtime_disable(dev);
goto err_remove_sysfs;
}
}
return 0;
err_remove_sysfs:
iommu_device_sysfs_remove(&iommu->iommu);