media: iommu/mediatek: Add probe_defer for smi-larb

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@mediatek.com>
Tested-by: Frank Wunderlich <frank-w@public-files.de> # BPI-R2/MT7623
Acked-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 77ae20ff9b35676ddc0d20b4000a055f6c04cb3f..5cff5bc556d4d9873fdbf75621c8c6d5092088bb 100644 (file)
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -850,6 +850,10 @@ 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 68bf02f87cfd198277daa7415c47aa9856fff809..4089077256f423e5e65193524c9cfb125fb7de6b 100644 (file)
--- 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,