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Message-ID: <20210929013719.25120-5-yong.wu@mediatek.com>
Date: Wed, 29 Sep 2021 09:37:11 +0800
From: Yong Wu <yong.wu@...iatek.com>
To: Matthias Brugger <matthias.bgg@...il.com>,
Joerg Roedel <joro@...tes.org>,
Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>,
David Airlie <airlied@...ux.ie>,
"Mauro Carvalho Chehab" <mchehab@...nel.org>
CC: Evan Green <evgreen@...omium.org>,
Robin Murphy <robin.murphy@....com>,
Tomasz Figa <tfiga@...omium.org>,
Will Deacon <will.deacon@....com>,
<linux-mediatek@...ts.infradead.org>,
<srv_heupstream@...iatek.com>, <devicetree@...r.kernel.org>,
<linux-kernel@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>,
<iommu@...ts.linux-foundation.org>, <yong.wu@...iatek.com>,
<youlin.pei@...iatek.com>, Matthias Kaehlcke <mka@...omium.org>,
<anan.sun@...iatek.com>, <yi.kuo@...iatek.com>,
<acourbot@...omium.org>, <linux-media@...r.kernel.org>,
<dri-devel@...ts.freedesktop.org>, Daniel Vetter <daniel@...ll.ch>,
Chun-Kuang Hu <chunkuang.hu@...nel.org>,
Philipp Zabel <p.zabel@...gutronix.de>,
Tiffany Lin <tiffany.lin@...iatek.com>,
"Dafna Hirschfeld" <dafna.hirschfeld@...labora.com>,
Hsin-Yi Wang <hsinyi@...omium.org>,
Eizan Miyamoto <eizan@...omium.org>,
<anthony.huang@...iatek.com>,
Frank Wunderlich <frank-w@...lic-files.de>
Subject: [PATCH v8 04/12] 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.
[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@...omium.org>
Signed-off-by: Yong Wu <yong.wu@...iatek.com>
Tested-by: Frank Wunderlich <frank-w@...lic-files.de> # BPI-R2/MT7623
---
drivers/iommu/mtk_iommu.c | 22 ++++++++++++++++++++++
drivers/iommu/mtk_iommu_v1.c | 20 +++++++++++++++++++-
2 files changed, 41 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index d5848f78a677..a2fa55899434 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -560,22 +560,44 @@ 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;
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 in each a larb is a independent HW. thus only link
+ * one larb here.
+ */
+ larbid = MTK_M4U_TO_LARB(fwspec->ids[0]);
+ 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);
}
diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index 4d7809432239..e6f13459470e 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;
+ struct device_link *link;
+ struct device *larbdev;
/*
* In the deferred case, free the existed fwspec.
@@ -453,6 +455,14 @@ 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]);
+ 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 +483,18 @@ 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);
}
--
2.18.0
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