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media: iommu/mediatek: Add device_link between the consumer and the larb devices

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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>
This commit is contained in:
Yong Wu 2022-01-17 08:05:02 +01:00 committed by Mauro Carvalho Chehab
parent 7d09aaf831
commit 635319a4a7
2 changed files with 58 additions and 1 deletions
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30
drivers/iommu/mtk_iommu.c
View file

@ -562,22 +562,52 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev)
{
struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
struct mtk_iommu_data *data;
struct device_link *link;
struct device *larbdev;
unsigned int larbid, larbidx, i;
if (!fwspec || fwspec->ops != &mtk_iommu_ops)
return ERR_PTR(-ENODEV); /* Not a iommu client device */
data = dev_iommu_priv_get(dev);
/*
* Link the consumer device with the smi-larb device(supplier).
* The device that connects with each a larb is a independent HW.
* All the ports in each a device should be in the same larbs.
*/
larbid = MTK_M4U_TO_LARB(fwspec->ids[0]);
for (i = 1; i < fwspec->num_ids; i++) {
larbidx = MTK_M4U_TO_LARB(fwspec->ids[i]);
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;
}
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 = MTK_M4U_TO_LARB(fwspec->ids[0]);
larbdev = data->larb_imu[larbid].dev;
device_link_remove(dev, larbdev);
iommu_fwspec_free(dev);
}

29
drivers/iommu/mtk_iommu_v1.c
View file

@ -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);
}