'bad remote port parent' warnings

'bad remote port parent' warnings

[Fabio Estevam]

Hi,

On a imx6q-wandboard running linux-next 20181120 there the following warnings:

[    4.327794] video-mux 20e0000.iomuxc-gpr:ipu1_csi0_mux: bad remote
port parent
[    4.336118] video-mux 20e0000.iomuxc-gpr:ipu2_csi1_mux: bad remote
port parent

Is there anything we should do to prevent this from happening?

Thanks,

Fabio Estevam

Re: 'bad remote port parent' warnings

[Sakari Ailus]

On Tue, Nov 20, 2018 at 10:10:57AM -0200, Fabio Estevam wrote:
> Hi,
> 
> On a imx6q-wandboard running linux-next 20181120 there the following warnings:
> 
> [    4.327794] video-mux 20e0000.iomuxc-gpr:ipu1_csi0_mux: bad remote
> port parent
> [    4.336118] video-mux 20e0000.iomuxc-gpr:ipu2_csi1_mux: bad remote
> port parent
> 
> Is there anything we should do to prevent this from happening?

Where's the DT source for the board?

-- 
Sakari Ailus
sakari.ailus@linux.intel.com

Re: 'bad remote port parent' warnings

[Fabio Estevam]

Hi Sakari,

On Tue, Nov 20, 2018 at 10:15 AM Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:

> Where's the DT source for the board?

Board dts is arch/arm/boot/dts/imx6qdl-wandboard.dtsi

SoC dtsi is arch/arm/boot/dts/imx6q.dtsi

Also, since 4.20-rc the following errors are seen:

[    3.449564] imx-ipuv3 2400000.ipu: driver could not parse
port@1/endpoint@0 (-22)
[    3.457342] imx-ipuv3-csi: probe of imx-ipuv3-csi.1 failed with error -22
[    3.464498] imx-ipuv3 2800000.ipu: driver could not parse
port@0/endpoint@0 (-22)
[    3.472120] imx-ipuv3-csi: probe of imx-ipuv3-csi.4 failed with error -22

which were not present in 4.19.

Log from 4.19:
https://storage.kernelci.org/stable/linux-4.19.y/v4.19.2/arm/imx_v6_v7_defconfig/lab-baylibre-seattle/boot-imx6q-wandboard.html

Log from 4.20-rc3:
https://storage.kernelci.org/mainline/master/v4.20-rc3/arm/imx_v6_v7_defconfig/lab-baylibre-seattle/boot-imx6q-wandboard.html

Thanks

Re: 'bad remote port parent' warnings

[Philipp Zabel]

On Tue, 2018-11-20 at 10:10 -0200, Fabio Estevam wrote:
> Hi,
> 
> On a imx6q-wandboard running linux-next 20181120 there the following warnings:
> 
> [    4.327794] video-mux 20e0000.iomuxc-gpr:ipu1_csi0_mux: bad remote
> port parent
> [    4.336118] video-mux 20e0000.iomuxc-gpr:ipu2_csi1_mux: bad remote
> port parent
> 
> Is there anything we should do to prevent this from happening?

There are empty endpoint nodes (without remote-endpoint property)
labeled ipu1_csi[01]_mux_from_parallel_sensor in the i.MX6 device trees
for board DT implementers' convenience. See commit 2539f517acbdc ("ARM:
dts: imx6qdl: Add video multiplexers, mipi_csi, and their connections").

We had a discussion about this issue in February when this caused a
probing error: https://patchwork.kernel.org/patch/10234469/

We could demote the warning to a debug message, make the wording a bit
less misleading (there is no bad remote port parent, there is just no
remote endpoint at all), or we could just accept the error message for
old DTBs and mark these empty endpoint nodes with the /omit-if-no-ref/
keyword to let dtc remove them if they are unused.

regards
Philipp

Re: 'bad remote port parent' warnings

[Fabio Estevam]

Hi Philipp,

On Thu, Nov 22, 2018 at 2:27 PM Philipp Zabel <p.zabel@pengutronix.de> wrote:

> There are empty endpoint nodes (without remote-endpoint property)
> labeled ipu1_csi[01]_mux_from_parallel_sensor in the i.MX6 device trees
> for board DT implementers' convenience. See commit 2539f517acbdc ("ARM:
> dts: imx6qdl: Add video multiplexers, mipi_csi, and their connections").
>
> We had a discussion about this issue in February when this caused a
> probing error: https://patchwork.kernel.org/patch/10234469/

Thanks for the clarification.

 We could demote the warning to a debug message, make the wording a bit
> less misleading (there is no bad remote port parent, there is just no
> remote endpoint at all), or we could just accept the error message for

Something like this?

--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -613,7 +613,7 @@ v4l2_async_notifier_fwnode_parse_endpoint(struct
device *dev,
        asd->match.fwnode =
                fwnode_graph_get_remote_port_parent(endpoint);
        if (!asd->match.fwnode) {
-               dev_warn(dev, "bad remote port parent\n");
+               dev_dbg(dev, "no remote endpoint found\n");
                ret = -ENOTCONN;
                goto out_err;
        }

And how should we treat these error probes?

[    3.449564] imx-ipuv3 2400000.ipu: driver could not parse
port@1/endpoint@0 (-22)
[    3.457342] imx-ipuv3-csi: probe of imx-ipuv3-csi.1 failed with error -22
[    3.464498] imx-ipuv3 2800000.ipu: driver could not parse
port@0/endpoint@0 (-22)
[    3.472120] imx-ipuv3-csi: probe of imx-ipuv3-csi.4 failed with error -22

Thanks

Re: 'bad remote port parent' warnings

[Sakari Ailus]

Hi Fabio, Philipp,

On Thu, Nov 22, 2018 at 05:17:44PM -0200, Fabio Estevam wrote:
> Hi Philipp,
> 
> On Thu, Nov 22, 2018 at 2:27 PM Philipp Zabel <p.zabel@pengutronix.de> wrote:
> 
> > There are empty endpoint nodes (without remote-endpoint property)
> > labeled ipu1_csi[01]_mux_from_parallel_sensor in the i.MX6 device trees
> > for board DT implementers' convenience. See commit 2539f517acbdc ("ARM:
> > dts: imx6qdl: Add video multiplexers, mipi_csi, and their connections").
> >
> > We had a discussion about this issue in February when this caused a
> > probing error: https://patchwork.kernel.org/patch/10234469/
> 
> Thanks for the clarification.
> 
>  We could demote the warning to a debug message, make the wording a bit
> > less misleading (there is no bad remote port parent, there is just no
> > remote endpoint at all), or we could just accept the error message for
> 
> Something like this?
> 
> --- a/drivers/media/v4l2-core/v4l2-fwnode.c
> +++ b/drivers/media/v4l2-core/v4l2-fwnode.c
> @@ -613,7 +613,7 @@ v4l2_async_notifier_fwnode_parse_endpoint(struct
> device *dev,
>         asd->match.fwnode =
>                 fwnode_graph_get_remote_port_parent(endpoint);
>         if (!asd->match.fwnode) {
> -               dev_warn(dev, "bad remote port parent\n");
> +               dev_dbg(dev, "no remote endpoint found\n");

Makes sense. This is not necessarily a fatal error. Could you send a patch?

>                 ret = -ENOTCONN;
>                 goto out_err;
>         }
> 
> And how should we treat these error probes?
> 
> [    3.449564] imx-ipuv3 2400000.ipu: driver could not parse
> port@1/endpoint@0 (-22)
> [    3.457342] imx-ipuv3-csi: probe of imx-ipuv3-csi.1 failed with error -22
> [    3.464498] imx-ipuv3 2800000.ipu: driver could not parse
> port@0/endpoint@0 (-22)
> [    3.472120] imx-ipuv3-csi: probe of imx-ipuv3-csi.4 failed with error -22

I'm not sure if this is a real problem, I presume it's just that the device
has nothing connected to it, and so cannot work. Steve probably has a
better understanding of this, I'm just guessing here. :-)

-- 
Regards,

Sakari Ailus
sakari.ailus@linux.intel.com

Re: 'bad remote port parent' warnings

[Fabio Estevam]

Hi Sakari,

On Fri, Nov 23, 2018 at 10:35 AM Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:

> Makes sense. This is not necessarily a fatal error. Could you send a patch?

Yes, I have just sent it.

Thanks

Re: 'bad remote port parent' warnings

[Steve Longerbeam]

Hi Fabio,

On 11/22/18 11:17 AM, Fabio Estevam wrote:
> Hi Philipp,
>
> On Thu, Nov 22, 2018 at 2:27 PM Philipp Zabel <p.zabel@pengutronix.de> wrote:
>
>> There are empty endpoint nodes (without remote-endpoint property)
>> labeled ipu1_csi[01]_mux_from_parallel_sensor in the i.MX6 device trees
>> for board DT implementers' convenience. See commit 2539f517acbdc ("ARM:
>> dts: imx6qdl: Add video multiplexers, mipi_csi, and their connections").
>>
>> We had a discussion about this issue in February when this caused a
>> probing error: https://patchwork.kernel.org/patch/10234469/
> Thanks for the clarification.
>
>   We could demote the warning to a debug message, make the wording a bit
>> less misleading (there is no bad remote port parent, there is just no
>> remote endpoint at all), or we could just accept the error message for
> Something like this?
>
> --- a/drivers/media/v4l2-core/v4l2-fwnode.c
> +++ b/drivers/media/v4l2-core/v4l2-fwnode.c
> @@ -613,7 +613,7 @@ v4l2_async_notifier_fwnode_parse_endpoint(struct
> device *dev,
>          asd->match.fwnode =
>                  fwnode_graph_get_remote_port_parent(endpoint);
>          if (!asd->match.fwnode) {
> -               dev_warn(dev, "bad remote port parent\n");
> +               dev_dbg(dev, "no remote endpoint found\n");
>                  ret = -ENOTCONN;
>                  goto out_err;
>          }
>
> And how should we treat these error probes?
>
> [    3.449564] imx-ipuv3 2400000.ipu: driver could not parse
> port@1/endpoint@0 (-22)
> [    3.457342] imx-ipuv3-csi: probe of imx-ipuv3-csi.1 failed with error -22
> [    3.464498] imx-ipuv3 2800000.ipu: driver could not parse
> port@0/endpoint@0 (-22)
> [    3.472120] imx-ipuv3-csi: probe of imx-ipuv3-csi.4 failed with error -22

Yes, this is a regression caused by the imx subdev notifier patches. 
I've already sent a patch to the list for this, see

https://www.spinics.net/lists/linux-media/msg141809.html

Steve

Re: 'bad remote port parent' warnings

[Fabio Estevam]

Hi Steve,

On Fri, Nov 23, 2018 at 8:37 PM Steve Longerbeam <slongerbeam@gmail.com> wrote:

> Yes, this is a regression caused by the imx subdev notifier patches.
> I've already sent a patch to the list for this, see
>
> https://www.spinics.net/lists/linux-media/msg141809.html

Thanks, this fixes it.

Hopefully it will be applied as a fix for 4.20.

Thanks