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authorYong Wu <yong.wu@mediatek.com>2022-01-17 08:05:02 +0100
committerMauro Carvalho Chehab <mchehab@kernel.org>2022-01-28 15:30:21 +0100
commit635319a4a7444ca97124d781cd96deb277ff4d40 (patch)
tree508d4de23aa7ebcc66e3dc54191e53352d1ece1a /drivers/iommu/mtk_iommu_v1.c
parentmedia: iommu/mediatek: Add probe_defer for smi-larb (diff)
downloadlinux-635319a4a7444ca97124d781cd96deb277ff4d40.tar.xz
linux-635319a4a7444ca97124d781cd96deb277ff4d40.zip
media: iommu/mediatek: Add device_link between the consumer and the larb devices
MediaTek IOMMU-SMI diagram is like below. all the consumer connect with smi-larb, then connect with smi-common. M4U | smi-common | ------------- | | ... | | larb1 larb2 | | vdec venc When the consumer works, it should enable the smi-larb's power which also need enable the smi-common's power firstly. Thus, First of all, use the device link connect the consumer and the smi-larbs. then add device link between the smi-larb and smi-common. This patch adds device_link between the consumer and the larbs. When device_link_add, I add the flag DL_FLAG_STATELESS to avoid calling pm_runtime_xx to keep the original status of clocks. It can avoid two issues: 1) Display HW show fastlogo abnormally reported in [1]. At the beggining, all the clocks are enabled before entering kernel, but the clocks for display HW(always in larb0) will be gated after clk_enable and clk_disable called from device_link_add(->pm_runtime_resume) and rpm_idle. The clock operation happened before display driver probe. At that time, the display HW will be abnormal. 2) A deadlock issue reported in [2]. Use DL_FLAG_STATELESS to skip pm_runtime_xx to avoid the deadlock. Corresponding, DL_FLAG_AUTOREMOVE_CONSUMER can't be added, then device_link_removed should be added explicitly. Meanwhile, Currently we don't have a device connect with 2 larbs at the same time. Disallow this case, print the error log. [1] https://lore.kernel.org/linux-mediatek/1564213888.22908.4.camel@mhfsdcap03/ [2] https://lore.kernel.org/patchwork/patch/1086569/ Suggested-by: Tomasz Figa <tfiga@chromium.org> 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>
Diffstat (limited to 'drivers/iommu/mtk_iommu_v1.c')
-rw-r--r--drivers/iommu/mtk_iommu_v1.c29
1 files changed, 28 insertions, 1 deletions
diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index 4089077256f4..4052aad75a81 100644
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -423,7 +423,9 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev)
struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
struct of_phandle_args iommu_spec;
struct mtk_iommu_data *data;
- int err, idx = 0;
+ int err, idx = 0, larbid, larbidx;
+ struct device_link *link;
+ struct device *larbdev;
/*
* In the deferred case, free the existed fwspec.
@@ -453,6 +455,23 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev)
data = dev_iommu_priv_get(dev);
+ /* Link the consumer device with the smi-larb device(supplier) */
+ larbid = mt2701_m4u_to_larb(fwspec->ids[0]);
+ for (idx = 1; idx < fwspec->num_ids; idx++) {
+ larbidx = mt2701_m4u_to_larb(fwspec->ids[idx]);
+ if (larbid != larbidx) {
+ dev_err(dev, "Can only use one larb. Fail@larb%d-%d.\n",
+ larbid, larbidx);
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ larbdev = data->larb_imu[larbid].dev;
+ link = device_link_add(dev, larbdev,
+ DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS);
+ if (!link)
+ dev_err(dev, "Unable to link %s\n", dev_name(larbdev));
+
return &data->iommu;
}
@@ -473,10 +492,18 @@ static void mtk_iommu_probe_finalize(struct device *dev)
static void mtk_iommu_release_device(struct device *dev)
{
struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+ struct mtk_iommu_data *data;
+ struct device *larbdev;
+ unsigned int larbid;
if (!fwspec || fwspec->ops != &mtk_iommu_ops)
return;
+ data = dev_iommu_priv_get(dev);
+ larbid = mt2701_m4u_to_larb(fwspec->ids[0]);
+ larbdev = data->larb_imu[larbid].dev;
+ device_link_remove(dev, larbdev);
+
iommu_fwspec_free(dev);
}