[PATCH V2 3/3] iommu/rockchip: ignore isp mmu reset operation

Simon Xue
2017-07-21T06:27:10Z

From: Simon <xxm@rock-chips.com>

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 <xxm@rock-chips.com>
---
changes since V1:
- use '-' instead of '_' for DT property.

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 3c462c0..3c6dc81 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.
@@ -1177,6 +1181,9 @@ static int rk_iommu_probe(struct platform_device *pdev)
}
}

+ iommu->reset_disabled = device_property_read_bool(dev,
+ "rk-iommu,disable-reset-quirk");
+
err = iommu_device_sysfs_add(&iommu->iommu, dev, NULL, dev_name(dev));
if (err)
return err;
--
1.9.1