From: Simon <xxm@xxxxxxxxxxxxxx> 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 at 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