Prepare for adding device_link. The iommu consumer should use device_link to connect with the smi-larb(supplier). then the smi-larb should run before the iommu consumer. Here we delay the iommu driver until the smi driver is ready, then all the iommu consumers always are after the smi driver. When there is no this patch, if some consumer drivers run before smi-larb, the supplier link_status is DL_DEV_NO_DRIVER(0) in the device_link_add, then device_links_driver_bound will use WARN_ON to complain that the link_status of supplier is not right. device_is_bound may be more elegant here. but it is not allowed to EXPORT from https://lore.kernel.org/patchwork/patch/1334670/. Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx> Tested-by: Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx> # BPI-R2/MT7623 --- drivers/iommu/mtk_iommu.c | 4 ++++ drivers/iommu/mtk_iommu_v1.c | 4 ++++ 2 files changed, 8 insertions(+) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 8f566d2e72e5..0033c0634e5e 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -848,6 +848,10 @@ static int mtk_iommu_probe(struct platform_device *pdev) of_node_put(larbnode); return -ENODEV; } + if (!plarbdev->dev.driver) { + of_node_put(larbnode); + return -EPROBE_DEFER; + } data->larb_imu[id].dev = &plarbdev->dev; component_match_add_release(dev, &match, release_of, diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c index 68bf02f87cfd..4089077256f4 100644 --- a/drivers/iommu/mtk_iommu_v1.c +++ b/drivers/iommu/mtk_iommu_v1.c @@ -606,6 +606,10 @@ static int mtk_iommu_probe(struct platform_device *pdev) of_node_put(larbnode); return -ENODEV; } + if (!plarbdev->dev.driver) { + of_node_put(larbnode); + return -EPROBE_DEFER; + } data->larb_imu[i].dev = &plarbdev->dev; component_match_add_release(dev, &match, release_of, -- 2.18.0
