[PATCH 4.9 005/111] iommu/arm-smmu-v3: sync the OVACKFLG to PRIQ consumer register

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Miao Zhong <zhongmiao@xxxxxxxxxxxxx>

[ Upstream commit 0d535967ac658966c6ade8f82b5799092f7d5441 ]

When PRI queue occurs overflow, driver should update the OVACKFLG to
the PRIQ consumer register, otherwise subsequent PRI requests will not
be processed.

Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Signed-off-by: Miao Zhong <zhongmiao@xxxxxxxxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/iommu/arm-smmu-v3.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1233,6 +1233,7 @@ static irqreturn_t arm_smmu_priq_thread(
 
 	/* Sync our overflow flag, as we believe we're up to speed */
 	q->cons = Q_OVF(q, q->prod) | Q_WRP(q, q->cons) | Q_IDX(q, q->cons);
+	writel(q->cons, q->cons_reg);
 	return IRQ_HANDLED;
 }