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From 70c45286e5697f4b2173a7dd9fc722375a9cfb37 Mon Sep 17 00:00:00 2001
From: Simon Xue <xxm@rock-chips.com>
Date: Mon, 24 Jul 2017 10:37:15 +0800
Subject: [PATCH 14/86] iommu/rockchip: ignore isp mmu reset operation

Git-commit: c3aa47424918acdfed8982d5a3588351ebefdfc1
Patch-mainline: v4.14-rc1
References: fate#323912

ISP mmu can't support reset operation, it won't get the
expected result when reset, but rest functions work normally.
Add this patch as a WA for this issue.

Signed-off-by: Simon Xue <xxm@rock-chips.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
 drivers/iommu/rockchip-iommu.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index e2852b041231..78ea341c7c75 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -92,6 +92,7 @@ struct rk_iommu {
 	int num_mmu;
 	int *irq;
 	int num_irq;
+	bool reset_disabled;
 	struct iommu_device iommu;
 	struct list_head node; /* entry in rk_iommu_domain.iommus */
 	struct iommu_domain *domain; /* domain to which iommu is attached */
@@ -415,6 +416,9 @@ static int rk_iommu_force_reset(struct rk_iommu *iommu)
 	int ret, i;
 	u32 dte_addr;
 
+	if (iommu->reset_disabled)
+		return 0;
+
 	/*
 	 * Check if register DTE_ADDR is working by writing DTE_ADDR_DUMMY
 	 * and verifying that upper 5 nybbles are read back.
@@ -1180,6 +1184,9 @@ static int rk_iommu_probe(struct platform_device *pdev)
 		}
 	}
 
+	iommu->reset_disabled = device_property_read_bool(dev,
+					"rockchip,disable-mmu-reset");
+
 	err = iommu_device_sysfs_add(&iommu->iommu, dev, NULL, dev_name(dev));
 	if (err)
 		return err;
-- 
2.11.0