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From: heiko@sntech.de (Heiko Stuebner)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] iommu/rockchip: Move irq request past pm_runtime_enable
Date: Tue, 07 Aug 2018 13:45:26 +0200	[thread overview]
Message-ID: <2114757.JfhfUCyzvi@phil> (raw)
In-Reply-To: <20180807085406.3863-3-marc.zyngier@arm.com>

Am Dienstag, 7. August 2018, 10:54:06 CEST schrieb Marc Zyngier:
> 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")
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Reviewed-by: Heiko Stuebner <heiko@sntech.de>

      reply	other threads:[~2018-08-07 11:45 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-07  8:54 [PATCH 0/2] iommu/rockchip: Runtime PM fixes Marc Zyngier
2018-08-07  8:54 ` [PATCH 1/2] iommu/rockchip: Handle errors returned from PM framework Marc Zyngier
2018-08-07 12:09   ` Heiko Stuebner
2018-08-07 12:31     ` Marc Zyngier
2018-08-07 13:15       ` Heiko Stuebner
2018-08-07 14:25         ` Marc Zyngier
2018-08-08  6:30           ` Heiko Stuebner
2018-08-08  6:33   ` Heiko Stuebner
2018-08-07  8:54 ` [PATCH 2/2] iommu/rockchip: Move irq request past pm_runtime_enable Marc Zyngier
2018-08-07 11:45   ` Heiko Stuebner [this message]

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