On Wed, Oct 09, 2019 at 09:19:02PM +0800, Yong Wu wrote: > Use writel for the register F_MMU_INV_RANGE which is for triggering the > HW work. We expect all the setting(iova_start/iova_end...) have already > been finished before F_MMU_INV_RANGE. > > Signed-off-by: Anan.Sun <anan....@mediatek.com> > Signed-off-by: Yong Wu <yong...@mediatek.com> > --- > This is a improvement rather than fixing a issue. > --- > drivers/iommu/mtk_iommu.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > index 24a13a6..607f92c 100644 > --- a/drivers/iommu/mtk_iommu.c > +++ b/drivers/iommu/mtk_iommu.c > @@ -187,8 +187,7 @@ static void mtk_iommu_tlb_add_flush(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); > + writel(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
I don't understand this change. Why is it an "improvement" and which accesses are you ordering with the writel? Will