subject:"\[PATCH v3 03\/14\] iommu\/mediatek\: Add device_link between the consumer and the larb devices"

Re: [PATCH v3 03/14] iommu/mediatek: Add device_link between the consumer and the larb devices

2020-03-05 Thread Yong Wu

On Thu, 2020-03-05 at 13:14 +0800, Nicolas Boichat wrote:
> On Tue, Sep 3, 2019 at 5:38 PM Yong Wu  wrote:
> >
> > MediaTek IOMMU don't have its power-domain. 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] http://lists.infradead.org/pipermail/linux-mediatek/2019-July/
> > 021500.html
> > [2] https://lore.kernel.org/patchwork/patch/1086569/
> >
> > Suggested-by: Tomasz Figa 
> > Signed-off-by: Yong Wu 
> > ---
> >  drivers/iommu/mtk_iommu.c| 17 +
> >  drivers/iommu/mtk_iommu_v1.c | 18 +-
> >  2 files changed, 34 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> > index b138b94..2511b3c 100644
> > --- a/drivers/iommu/mtk_iommu.c
> > +++ b/drivers/iommu/mtk_iommu.c
> > @@ -450,6 +450,9 @@ static int mtk_iommu_add_device(struct device *dev)
> > struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
> > struct mtk_iommu_data *data;
> > struct iommu_group *group;
> > +   struct device_link *link;
> > +   struct device *larbdev;
> > +   unsigned int larbid;
> >
> > if (!fwspec || fwspec->ops != _iommu_ops)
> > return -ENODEV; /* Not a iommu client device */
> > @@ -461,6 +464,14 @@ static int mtk_iommu_add_device(struct device *dev)
> > if (IS_ERR(group))
> > return PTR_ERR(group);
> >
> > +   /* Link the consumer device with the smi-larb device(supplier) */
> > +   larbid = MTK_M4U_TO_LARB(fwspec->ids[0]);
> 
> I'll mirror the comment I made on gerrit
> (https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1361013):
> Maybe I'm missing something here, but for example, on MT8173,
> vcodec_enc: vcodec@18002000 needs to use both larb3 and larb5, isn't
> the code below just adding a link for larb3?

Yes. It only add larb3 here.

> 
> Do we need to iterate over all fwspecs->ids to figure out which larbs
> we need to add links to each of them?

We have checked this venc issue. Currently I have requested our venc guy
to seperate larb3-venc and larb5-venc in the driver[1] since they are
independent HW actually. I will put it into this series when I send next
version.

If there is some reasonable driver which have two larbs in it, then the
iterating is really necessary, But I don't see it right now. Only using
fwspec->ids[0] is enough for now.

[1]
https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1958322

> 
> > +   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));
> > +
> > iommu_group_put(group);
> > return 0;
> >  }
> > @@ -469,6 +480,8 @@ static void mtk_iommu_remove_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 != _iommu_ops)
> > return;
> > @@ -476,6 +489,10 @@ static void mtk_iommu_remove_device(struct device *dev)
> > data = fwspec->iommu_priv;
> > iommu_device_unlink(>iommu, dev);
> >
> > +   larbid = MTK_M4U_TO_LARB(fwspec->ids[0]);
> > +   larbdev = data->larb_imu[larbid].dev;
> > +   device_link_remove(dev, larbdev);
> > +
> > iommu_group_remove_device(dev);
> > iommu_fwspec_free(dev);
> >  }
> > diff --git

Re: [PATCH v3 03/14] iommu/mediatek: Add device_link between the consumer and the larb devices

2020-03-04 Thread Nicolas Boichat

On Tue, Sep 3, 2019 at 5:38 PM Yong Wu  wrote:
>
> MediaTek IOMMU don't have its power-domain. 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] http://lists.infradead.org/pipermail/linux-mediatek/2019-July/
> 021500.html
> [2] https://lore.kernel.org/patchwork/patch/1086569/
>
> Suggested-by: Tomasz Figa 
> Signed-off-by: Yong Wu 
> ---
>  drivers/iommu/mtk_iommu.c| 17 +
>  drivers/iommu/mtk_iommu_v1.c | 18 +-
>  2 files changed, 34 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index b138b94..2511b3c 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -450,6 +450,9 @@ static int mtk_iommu_add_device(struct device *dev)
> struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
> struct mtk_iommu_data *data;
> struct iommu_group *group;
> +   struct device_link *link;
> +   struct device *larbdev;
> +   unsigned int larbid;
>
> if (!fwspec || fwspec->ops != _iommu_ops)
> return -ENODEV; /* Not a iommu client device */
> @@ -461,6 +464,14 @@ static int mtk_iommu_add_device(struct device *dev)
> if (IS_ERR(group))
> return PTR_ERR(group);
>
> +   /* Link the consumer device with the smi-larb device(supplier) */
> +   larbid = MTK_M4U_TO_LARB(fwspec->ids[0]);

I'll mirror the comment I made on gerrit
(https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1361013):
Maybe I'm missing something here, but for example, on MT8173,
vcodec_enc: vcodec@18002000 needs to use both larb3 and larb5, isn't
the code below just adding a link for larb3?

Do we need to iterate over all fwspecs->ids to figure out which larbs
we need to add links to each of them?

> +   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));
> +
> iommu_group_put(group);
> return 0;
>  }
> @@ -469,6 +480,8 @@ static void mtk_iommu_remove_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 != _iommu_ops)
> return;
> @@ -476,6 +489,10 @@ static void mtk_iommu_remove_device(struct device *dev)
> data = fwspec->iommu_priv;
> iommu_device_unlink(>iommu, dev);
>
> +   larbid = MTK_M4U_TO_LARB(fwspec->ids[0]);
> +   larbdev = data->larb_imu[larbid].dev;
> +   device_link_remove(dev, larbdev);
> +
> iommu_group_remove_device(dev);
> iommu_fwspec_free(dev);
>  }
> diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
> index 2034d72..a7f22a2 100644
> --- a/drivers/iommu/mtk_iommu_v1.c
> +++ b/drivers/iommu/mtk_iommu_v1.c
> @@ -423,7 +423,9 @@ static int mtk_iommu_add_device(struct device *dev)
> struct of_phandle_iterator it;
> struct mtk_iommu_data *data;
> struct iommu_group *group;
> -   int err;
> +   struct device_link *link;
> +   struct device *larbdev;
> +   int err, larbid;
>
> of_for_each_phandle(, err, dev->of_node, "iommus",
> "#iommu-cells", 0) {
> @@ -466,6 +468,14 @@ static int mtk_iommu_add_device(struct device *dev)
> return err;
> }
>
> +   /* Link the consumer device with the smi-larb device(supplier) */
> +   larbid =

[PATCH v3 03/14] iommu/mediatek: Add device_link between the consumer and the larb devices

2019-09-03 Thread Yong Wu

MediaTek IOMMU don't have its power-domain. 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] http://lists.infradead.org/pipermail/linux-mediatek/2019-July/
021500.html
[2] https://lore.kernel.org/patchwork/patch/1086569/

Suggested-by: Tomasz Figa 
Signed-off-by: Yong Wu 
---
 drivers/iommu/mtk_iommu.c| 17 +
 drivers/iommu/mtk_iommu_v1.c | 18 +-
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index b138b94..2511b3c 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -450,6 +450,9 @@ static int mtk_iommu_add_device(struct device *dev)
struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
struct mtk_iommu_data *data;
struct iommu_group *group;
+   struct device_link *link;
+   struct device *larbdev;
+   unsigned int larbid;
 
if (!fwspec || fwspec->ops != _iommu_ops)
return -ENODEV; /* Not a iommu client device */
@@ -461,6 +464,14 @@ static int mtk_iommu_add_device(struct device *dev)
if (IS_ERR(group))
return PTR_ERR(group);
 
+   /* Link the consumer device with the smi-larb device(supplier) */
+   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));
+
iommu_group_put(group);
return 0;
 }
@@ -469,6 +480,8 @@ static void mtk_iommu_remove_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 != _iommu_ops)
return;
@@ -476,6 +489,10 @@ static void mtk_iommu_remove_device(struct device *dev)
data = fwspec->iommu_priv;
iommu_device_unlink(>iommu, dev);
 
+   larbid = MTK_M4U_TO_LARB(fwspec->ids[0]);
+   larbdev = data->larb_imu[larbid].dev;
+   device_link_remove(dev, larbdev);
+
iommu_group_remove_device(dev);
iommu_fwspec_free(dev);
 }
diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index 2034d72..a7f22a2 100644
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -423,7 +423,9 @@ static int mtk_iommu_add_device(struct device *dev)
struct of_phandle_iterator it;
struct mtk_iommu_data *data;
struct iommu_group *group;
-   int err;
+   struct device_link *link;
+   struct device *larbdev;
+   int err, larbid;
 
of_for_each_phandle(, err, dev->of_node, "iommus",
"#iommu-cells", 0) {
@@ -466,6 +468,14 @@ static int mtk_iommu_add_device(struct device *dev)
return err;
}
 
+   /* 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 iommu_device_link(>iommu, dev);
 }
 
@@ -473,6 +483,8 @@ static void mtk_iommu_remove_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 != _iommu_ops)
return;
@@ -480,6 +492,10 @@ static

Re: [PATCH v3 03/14] iommu/mediatek: Add device_link between the consumer and the larb devices

Re: [PATCH v3 03/14] iommu/mediatek: Add device_link between the consumer and the larb devices

[PATCH v3 03/14] iommu/mediatek: Add device_link between the consumer and the larb devices

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