From 822a2ed8c606caf6a11b1a180b8e46292bd77d71 Mon Sep 17 00:00:00 2001 From: Yong Wu Date: Mon, 17 Jan 2022 08:04:59 +0100 Subject: [PATCH] media: iommu/mediatek-v1: Free the existed fwspec if the master dev already has When the iommu master device enters of_iommu_xlate, the ops may be NULL(iommu dev is defered), then it will initialize the fwspec here: [] (dev_iommu_fwspec_set) from [] (iommu_fwspec_init+0xbc/0xd4) [] (iommu_fwspec_init) from [] (of_iommu_xlate+0x7c/0x12c) [] (of_iommu_xlate) from [] (of_iommu_configure+0x144/0x1e8) BUT the mtk_iommu_v1.c only supports arm32, the probing flow still is a bit weird. We always expect create the fwspec internally. otherwise it will enter here and return fail. static int mtk_iommu_create_mapping(struct device *dev, struct of_phandle_args *args) { ... if (!fwspec) { .... } else if (dev_iommu_fwspec_get(dev)->ops != &mtk_iommu_ops) { >>>>>>>>>>Enter here. return fail.<<<<<<<<<<<< return -EINVAL; } ... } Thus, Free the existed fwspec if the master device already has fwspec. This issue is reported at: https://lore.kernel.org/linux-mediatek/trinity-7d9ebdc9-4849-4d93-bfb5-429dcb4ee449-1626253158870@3c-app-gmx-bs01/ Reported-by: Frank Wunderlich Tested-by: Frank Wunderlich # BPI-R2/MT7623 Signed-off-by: Yong Wu Acked-by: Joerg Roedel Acked-by: AngeloGioacchino Del Regno Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/iommu/mtk_iommu_v1.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c index be22fcf..1467ba1 100644 --- a/drivers/iommu/mtk_iommu_v1.c +++ b/drivers/iommu/mtk_iommu_v1.c @@ -425,6 +425,15 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) struct mtk_iommu_data *data; int err, idx = 0; + /* + * In the deferred case, free the existed fwspec. + * Always initialize the fwspec internally. + */ + if (fwspec) { + iommu_fwspec_free(dev); + fwspec = dev_iommu_fwspec_get(dev); + } + while (!of_parse_phandle_with_args(dev->of_node, "iommus", "#iommu-cells", idx, &iommu_spec)) { -- 2.7.4