diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index e93906d6e112..c2764891a779 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -258,6 +258,8 @@ struct mtk_iommu_data {
 	struct device			*smicomm_dev;
 
 	struct mtk_iommu_bank_data	*bank;
+	struct mtk_iommu_domain		*share_dom; /* For 2 HWs share pgtable */
+
 	struct regmap			*pericfg;
 	struct mutex			mutex; /* Protect m4u_group/m4u_dom above */
 
@@ -620,15 +622,14 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom,
 				     struct mtk_iommu_data *data,
 				     unsigned int region_id)
 {
+	struct mtk_iommu_domain	*share_dom = data->share_dom;
 	const struct mtk_iommu_iova_region *region;
-	struct mtk_iommu_domain	*m4u_dom;
 
-	/* Always use bank0 in sharing pgtable case */
-	m4u_dom = data->bank[0].m4u_dom;
-	if (m4u_dom) {
-		dom->iop = m4u_dom->iop;
-		dom->cfg = m4u_dom->cfg;
-		dom->domain.pgsize_bitmap = m4u_dom->cfg.pgsize_bitmap;
+	/* Always use share domain in sharing pgtable case */
+	if (MTK_IOMMU_HAS_FLAG(data->plat_data, SHARE_PGTABLE) && share_dom) {
+		dom->iop = share_dom->iop;
+		dom->cfg = share_dom->cfg;
+		dom->domain.pgsize_bitmap = share_dom->cfg.pgsize_bitmap;
 		goto update_iova_region;
 	}
 
@@ -658,6 +659,9 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom,
 	/* Update our support page sizes bitmap */
 	dom->domain.pgsize_bitmap = dom->cfg.pgsize_bitmap;
 
+	if (MTK_IOMMU_HAS_FLAG(data->plat_data, SHARE_PGTABLE))
+		data->share_dom = dom;
+
 update_iova_region:
 	/* Update the iova region for this domain */
 	region = data->plat_data->iova_region + region_id;
@@ -708,7 +712,9 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain,
 		/* Data is in the frstdata in sharing pgtable case. */
 		frstdata = mtk_iommu_get_frst_data(hw_list);
 
+		mutex_lock(&frstdata->mutex);
 		ret = mtk_iommu_domain_finalise(dom, frstdata, region_id);
+		mutex_unlock(&frstdata->mutex);
 		if (ret) {
 			mutex_unlock(&dom->mutex);
 			return ret;