Merge tag 'char-misc-4.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregk...

[karo-tx-linux.git] / drivers / iommu / mtk_iommu.c

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 5d14cd15198db5cb6361d060abf208260c086ebe..91c6d367ab3593b99a6c9cfb9be01855e8372af2 100644 (file)
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -129,6 +129,7 @@ static void mtk_iommu_tlb_add_flush_nosync(unsigned long iova, size_t size,
        writel_relaxed(iova, data->base + REG_MMU_INVLD_START_A);
        writel_relaxed(iova + size - 1, data->base + REG_MMU_INVLD_END_A);
        writel_relaxed(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
+       data->tlb_flush_active = true;
 }
 
 static void mtk_iommu_tlb_sync(void *cookie)
@@ -137,6 +138,10 @@ static void mtk_iommu_tlb_sync(void *cookie)
        int ret;
        u32 tmp;
 
+       /* Avoid timing out if there's nothing to wait for */
+       if (!data->tlb_flush_active)
+               return;
+
        ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE, tmp,
                                        tmp != 0, 10, 100000);
        if (ret) {
@@ -146,6 +151,7 @@ static void mtk_iommu_tlb_sync(void *cookie)
        }
        /* Clear the CPE status */
        writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
+       data->tlb_flush_active = false;
 }
 
 static const struct iommu_gather_ops mtk_iommu_gather_ops = {