HDCP Content Type Interface

HDCP Content Type Interface

[Lakha, Bhawanpreet]

[-- Attachment #1.1: Type: text/plain, Size: 956 bytes --]

Hi all,

This is regarding the recent hdcp content type patch that was merged into drm-misc. (https://patchwork.freedesktop.org/patch/320958/?series=57233&rev=11)

There are displays on the market that advertise HDCP 2.2 support and will pass authentication and encryption but will then show a corrupted/blue/black screen (the driver cannot detect this). These displays work with HDCP 1.4 without any issues. Due to the large number of HDCP-supporting devices on the market we might not be able to catch them with a blacklist.

From the user modes perspective, HDCP1.4 and HDCP2.2 Type0 are the same thing. Meaning that this interface doesn't allow us to force the hdcp version. Due to the problems mentioned above we might want to expose the ability for a user to force an HDCP downgrade to a certain level (e.g. 1.4) in case they experience problems.

What are your thoughts? and what would be a good way to deal with it?


Thanks,

Bhawan

[-- Attachment #1.2: Type: text/html, Size: 1771 bytes --]

[-- Attachment #2: Type: text/plain, Size: 159 bytes --]

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: HDCP Content Type Interface

[Jani Nikula]

On Mon, 09 Sep 2019, "Lakha, Bhawanpreet" <Bhawanpreet.Lakha@amd.com> wrote:
> Hi all,
>
> This is regarding the recent hdcp content type patch that was merged
> into
> drm-misc. (https://patchwork.freedesktop.org/patch/320958/?series=57233&rev=11)
>
> There are displays on the market that advertise HDCP 2.2 support and
> will pass authentication and encryption but will then show a
> corrupted/blue/black screen (the driver cannot detect this). These
> displays work with HDCP 1.4 without any issues. Due to the large
> number of HDCP-supporting devices on the market we might not be able
> to catch them with a blacklist.

Has this been confirmed with some other HDCP source than the recently
merged HDCP 2.2 support? I.e. has it been confirmed the issue is really
in the sinks rather than in the source support?

BR,
Jani.


>
> From the user modes perspective, HDCP1.4 and HDCP2.2 Type0 are the
> same thing. Meaning that this interface doesn't allow us to force the
> hdcp version. Due to the problems mentioned above we might want to
> expose the ability for a user to force an HDCP downgrade to a certain
> level (e.g. 1.4) in case they experience problems.
>
> What are your thoughts? and what would be a good way to deal with it?
>
>
> Thanks,
>
> Bhawan
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Jani Nikula, Intel Open Source Graphics Center
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: HDCP Content Type Interface

[Ramalingam C]

On 2019-09-09 at 15:54:50 +0000, Lakha, Bhawanpreet wrote:
> Hi all,
> 
> This is regarding the recent hdcp content type patch that was merged into drm-misc. (https://patchwork.freedesktop.org/patch/320958/?series=57233&rev=11)
> 
> There are displays on the market that advertise HDCP 2.2 support and will pass authentication and encryption but will then show a corrupted/blue/black screen (the driver cannot detect this). These displays work with HDCP 1.4 without any issues. Due to the large number of HDCP-supporting devices on the market we might not be able to catch them with a blacklist.
> 
> From the user modes perspective, HDCP1.4 and HDCP2.2 Type0 are the same thing. Meaning that this interface doesn't allow us to force the hdcp version. Due to the problems mentioned above we might want to expose the ability for a user to force an HDCP downgrade to a certain level (e.g. 1.4) in case they experience problems.
> 
> What are your thoughts? and what would be a good way to deal with it?
Hi,

As you mentioned, uAPI is designed to be HDCP version agnostic. Kernel
supposed to exercise the highest version of HDCP supported on panel and
platform.

As we implement the HDCP spec support, if a device is non-compliant with
HDCP spec after completing the HDCP authentication, I dont think we need
to worry about it.

In case if you want to track and implement a quirk for it, like not to
project the HDCP2.2 capability, you can use the receiver id of that panel
to track it.

Thanks,
-Ram
> 
> 
> Thanks,
> 
> Bhawan
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: HDCP Content Type Interface

[Harry Wentland]

On 2019-09-12 3:47 a.m., Ramalingam C wrote:
> On 2019-09-09 at 15:54:50 +0000, Lakha, Bhawanpreet wrote:
>> Hi all,
>>
>> This is regarding the recent hdcp content type patch that was merged into drm-misc. (https://patchwork.freedesktop.org/patch/320958/?series=57233&rev=11)
>>
>> There are displays on the market that advertise HDCP 2.2 support and will pass authentication and encryption but will then show a corrupted/blue/black screen (the driver cannot detect this). These displays work with HDCP 1.4 without any issues. Due to the large number of HDCP-supporting devices on the market we might not be able to catch them with a blacklist.
>>
>> From the user modes perspective, HDCP1.4 and HDCP2.2 Type0 are the same thing. Meaning that this interface doesn't allow us to force the hdcp version. Due to the problems mentioned above we might want to expose the ability for a user to force an HDCP downgrade to a certain level (e.g. 1.4) in case they experience problems.
>>
>> What are your thoughts? and what would be a good way to deal with it?
> Hi,
> 
> As you mentioned, uAPI is designed to be HDCP version agnostic. Kernel
> supposed to exercise the highest version of HDCP supported on panel and
> platform.
> 
> As we implement the HDCP spec support, if a device is non-compliant with
> HDCP spec after completing the HDCP authentication, I dont think we need
> to worry about it.
> 

Tell that to our (or your) customers.

In this case an enduser might plug in a bad monitor or TV and be unable
to play protected content.

What if we add a new enum value to the content_type property that says
"DRM_MODE_HDCP_CONTENT_TYPE_FORCE_14"?

Harry

> In case if you want to track and implement a quirk for it, like not to
> project the HDCP2.2 capability, you can use the receiver id of that panel
> to track it.
> 
> Thanks,
> -Ram
>>
>>
>> Thanks,
>>
>> Bhawan
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: HDCP Content Type Interface

[Ramalingam C]

On 2019-09-12 at 14:23:05 +0000, Harry Wentland wrote:
> On 2019-09-12 3:47 a.m., Ramalingam C wrote:
> > On 2019-09-09 at 15:54:50 +0000, Lakha, Bhawanpreet wrote:
> >> Hi all,
> >>
> >> This is regarding the recent hdcp content type patch that was merged into drm-misc. (https://patchwork.freedesktop.org/patch/320958/?series=57233&rev=11)
> >>
> >> There are displays on the market that advertise HDCP 2.2 support and will pass authentication and encryption but will then show a corrupted/blue/black screen (the driver cannot detect this). These displays work with HDCP 1.4 without any issues. Due to the large number of HDCP-supporting devices on the market we might not be able to catch them with a blacklist.
> >>
> >> From the user modes perspective, HDCP1.4 and HDCP2.2 Type0 are the same thing. Meaning that this interface doesn't allow us to force the hdcp version. Due to the problems mentioned above we might want to expose the ability for a user to force an HDCP downgrade to a certain level (e.g. 1.4) in case they experience problems.
> >>
> >> What are your thoughts? and what would be a good way to deal with it?
> > Hi,
> > 
> > As you mentioned, uAPI is designed to be HDCP version agnostic. Kernel
> > supposed to exercise the highest version of HDCP supported on panel and
> > platform.
> > 
> > As we implement the HDCP spec support, if a device is non-compliant with
> > HDCP spec after completing the HDCP authentication, I dont think we need
> > to worry about it.
> > 
> 
> Tell that to our (or your) customers.
> 
> In this case an enduser might plug in a bad monitor or TV and be unable
> to play protected content.
> 
> What if we add a new enum value to the content_type property that says
> "DRM_MODE_HDCP_CONTENT_TYPE_FORCE_14"?
"content type" is for defining the stream type. Adding an entry into it
sounds like polluting it.

Separate uAPI for forcing a HDCP version might be need. Or wondering on
using the sysfs of connector for this dirty job!?

-Ram
> 
> Harry
> 
> > In case if you want to track and implement a quirk for it, like not to
> > project the HDCP2.2 capability, you can use the receiver id of that panel
> > to track it.
> > 
> > Thanks,
> > -Ram
> >>
> >>
> >> Thanks,
> >>
> >> Bhawan
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: HDCP Content Type Interface

[Jani Nikula]

On Thu, 12 Sep 2019, Harry Wentland <hwentlan@amd.com> wrote:
> On 2019-09-12 3:47 a.m., Ramalingam C wrote:
>> On 2019-09-09 at 15:54:50 +0000, Lakha, Bhawanpreet wrote:
>>> Hi all,
>>>
>>> This is regarding the recent hdcp content type patch that was merged into drm-misc. (https://patchwork.freedesktop.org/patch/320958/?series=57233&rev=11)
>>>
>>> There are displays on the market that advertise HDCP 2.2 support and will pass authentication and encryption but will then show a corrupted/blue/black screen (the driver cannot detect this). These displays work with HDCP 1.4 without any issues. Due to the large number of HDCP-supporting devices on the market we might not be able to catch them with a blacklist.
>>>
>>> From the user modes perspective, HDCP1.4 and HDCP2.2 Type0 are the same thing. Meaning that this interface doesn't allow us to force the hdcp version. Due to the problems mentioned above we might want to expose the ability for a user to force an HDCP downgrade to a certain level (e.g. 1.4) in case they experience problems.
>>>
>>> What are your thoughts? and what would be a good way to deal with it?
>> Hi,
>> 
>> As you mentioned, uAPI is designed to be HDCP version agnostic. Kernel
>> supposed to exercise the highest version of HDCP supported on panel and
>> platform.
>> 
>> As we implement the HDCP spec support, if a device is non-compliant with
>> HDCP spec after completing the HDCP authentication, I dont think we need
>> to worry about it.
>> 
>
> Tell that to our (or your) customers.

Agreed, let's rather not.

> In this case an enduser might plug in a bad monitor or TV and be unable
> to play protected content.
>
> What if we add a new enum value to the content_type property that says
> "DRM_MODE_HDCP_CONTENT_TYPE_FORCE_14"?

In general, I think if the fix is to teach the user to jump through
hoops in case the output is not working, it is really not a fix.

Would, say, a set top box or a Blu-ray player have a setting to force
HDCP 1.4, and a troubleshooting item in the manual to select that if the
display does not work? Or would OS X have that?

If broken HDCP 2.2 sink support is a widespread problem (is it?), what
do other HDCP sources do? If it's a Linux issue, what are we doing wrong
or different?


BR,
Jani.



>
> Harry
>
>> In case if you want to track and implement a quirk for it, like not to
>> project the HDCP2.2 capability, you can use the receiver id of that panel
>> to track it.
>> 
>> Thanks,
>> -Ram
>>>
>>>
>>> Thanks,
>>>
>>> Bhawan
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Jani Nikula, Intel Open Source Graphics Center
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: HDCP Content Type Interface

[Harry Wentland]

On 2019-09-12 10:49 a.m., Ramalingam C wrote:
> On 2019-09-12 at 14:23:05 +0000, Harry Wentland wrote:
>> On 2019-09-12 3:47 a.m., Ramalingam C wrote:
>>> On 2019-09-09 at 15:54:50 +0000, Lakha, Bhawanpreet wrote:
>>>> Hi all,
>>>>
>>>> This is regarding the recent hdcp content type patch that was merged into drm-misc. (https://patchwork.freedesktop.org/patch/320958/?series=57233&rev=11)
>>>>
>>>> There are displays on the market that advertise HDCP 2.2 support and will pass authentication and encryption but will then show a corrupted/blue/black screen (the driver cannot detect this). These displays work with HDCP 1.4 without any issues. Due to the large number of HDCP-supporting devices on the market we might not be able to catch them with a blacklist.
>>>>
>>>> From the user modes perspective, HDCP1.4 and HDCP2.2 Type0 are the same thing. Meaning that this interface doesn't allow us to force the hdcp version. Due to the problems mentioned above we might want to expose the ability for a user to force an HDCP downgrade to a certain level (e.g. 1.4) in case they experience problems.
>>>>
>>>> What are your thoughts? and what would be a good way to deal with it?
>>> Hi,
>>>
>>> As you mentioned, uAPI is designed to be HDCP version agnostic. Kernel
>>> supposed to exercise the highest version of HDCP supported on panel and
>>> platform.
>>>
>>> As we implement the HDCP spec support, if a device is non-compliant with
>>> HDCP spec after completing the HDCP authentication, I dont think we need
>>> to worry about it.
>>>
>>
>> Tell that to our (or your) customers.
>>
>> In this case an enduser might plug in a bad monitor or TV and be unable
>> to play protected content.
>>
>> What if we add a new enum value to the content_type property that says
>> "DRM_MODE_HDCP_CONTENT_TYPE_FORCE_14"?
> "content type" is for defining the stream type. Adding an entry into it
> sounds like polluting it.
> 

For sure

> Separate uAPI for forcing a HDCP version might be need. Or wondering on
> using the sysfs of connector for this dirty job!?
> 

Did a bit more digging...

On other OS we got a monitor quirk for a few displays and also something
similar to a module parameter to force disable HDCP 2.x support.

It looks like there aren't too many quirky receivers so that might be an
acceptable solution. I'm still thinking a connector property might be
useful to force a certain HDCP version but maybe I'm overthinking it.

Harry

> -Ram
>>
>> Harry
>>
>>> In case if you want to track and implement a quirk for it, like not to
>>> project the HDCP2.2 capability, you can use the receiver id of that panel
>>> to track it.
>>>
>>> Thanks,
>>> -Ram
>>>>
>>>>
>>>> Thanks,
>>>>
>>>> Bhawan
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: HDCP Content Type Interface

[Harry Wentland]

On 2019-09-12 10:57 a.m., Jani Nikula wrote:
> On Thu, 12 Sep 2019, Harry Wentland <hwentlan@amd.com> wrote:
>> On 2019-09-12 3:47 a.m., Ramalingam C wrote:
>>> On 2019-09-09 at 15:54:50 +0000, Lakha, Bhawanpreet wrote:
>>>> Hi all,
>>>>
>>>> This is regarding the recent hdcp content type patch that was merged into drm-misc. (https://patchwork.freedesktop.org/patch/320958/?series=57233&rev=11)
>>>>
>>>> There are displays on the market that advertise HDCP 2.2 support and will pass authentication and encryption but will then show a corrupted/blue/black screen (the driver cannot detect this). These displays work with HDCP 1.4 without any issues. Due to the large number of HDCP-supporting devices on the market we might not be able to catch them with a blacklist.
>>>>
>>>> From the user modes perspective, HDCP1.4 and HDCP2.2 Type0 are the same thing. Meaning that this interface doesn't allow us to force the hdcp version. Due to the problems mentioned above we might want to expose the ability for a user to force an HDCP downgrade to a certain level (e.g. 1.4) in case they experience problems.
>>>>
>>>> What are your thoughts? and what would be a good way to deal with it?
>>> Hi,
>>>
>>> As you mentioned, uAPI is designed to be HDCP version agnostic. Kernel
>>> supposed to exercise the highest version of HDCP supported on panel and
>>> platform.
>>>
>>> As we implement the HDCP spec support, if a device is non-compliant with
>>> HDCP spec after completing the HDCP authentication, I dont think we need
>>> to worry about it.
>>>
>>
>> Tell that to our (or your) customers.
> 
> Agreed, let's rather not.
> 
>> In this case an enduser might plug in a bad monitor or TV and be unable
>> to play protected content.
>>
>> What if we add a new enum value to the content_type property that says
>> "DRM_MODE_HDCP_CONTENT_TYPE_FORCE_14"?
> 
> In general, I think if the fix is to teach the user to jump through
> hoops in case the output is not working, it is really not a fix.
> 
> Would, say, a set top box or a Blu-ray player have a setting to force
> HDCP 1.4, and a troubleshooting item in the manual to select that if the
> display does not work? Or would OS X have that?
> 

Not sure. AFAIU on other OS we're currently dealing with this through
monitor quirks. We can probably pull the same quirks to DRM.

> If broken HDCP 2.2 sink support is a widespread problem (is it?), what
> do other HDCP sources do? If it's a Linux issue, what are we doing wrong
> or different?

Not a Linux issue and not overly widespread. Looks like a handful of
receivers are problematic.

Harry

> 
> 
> BR,
> Jani.
> 
> 
> 
>>
>> Harry
>>
>>> In case if you want to track and implement a quirk for it, like not to
>>> project the HDCP2.2 capability, you can use the receiver id of that panel
>>> to track it.
>>>
>>> Thanks,
>>> -Ram
>>>>
>>>>
>>>> Thanks,
>>>>
>>>> Bhawan
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: HDCP Content Type Interface

[Daniel Vetter]

On Thu, Sep 12, 2019 at 9:21 PM Harry Wentland <hwentlan@amd.com> wrote:
>
>
>
> On 2019-09-12 10:57 a.m., Jani Nikula wrote:
> > On Thu, 12 Sep 2019, Harry Wentland <hwentlan@amd.com> wrote:
> >> On 2019-09-12 3:47 a.m., Ramalingam C wrote:
> >>> On 2019-09-09 at 15:54:50 +0000, Lakha, Bhawanpreet wrote:
> >>>> Hi all,
> >>>>
> >>>> This is regarding the recent hdcp content type patch that was merged into drm-misc. (https://patchwork.freedesktop.org/patch/320958/?series=57233&rev=11)
> >>>>
> >>>> There are displays on the market that advertise HDCP 2.2 support and will pass authentication and encryption but will then show a corrupted/blue/black screen (the driver cannot detect this). These displays work with HDCP 1.4 without any issues. Due to the large number of HDCP-supporting devices on the market we might not be able to catch them with a blacklist.
> >>>>
> >>>> From the user modes perspective, HDCP1.4 and HDCP2.2 Type0 are the same thing. Meaning that this interface doesn't allow us to force the hdcp version. Due to the problems mentioned above we might want to expose the ability for a user to force an HDCP downgrade to a certain level (e.g. 1.4) in case they experience problems.
> >>>>
> >>>> What are your thoughts? and what would be a good way to deal with it?
> >>> Hi,
> >>>
> >>> As you mentioned, uAPI is designed to be HDCP version agnostic. Kernel
> >>> supposed to exercise the highest version of HDCP supported on panel and
> >>> platform.
> >>>
> >>> As we implement the HDCP spec support, if a device is non-compliant with
> >>> HDCP spec after completing the HDCP authentication, I dont think we need
> >>> to worry about it.
> >>>
> >>
> >> Tell that to our (or your) customers.
> >
> > Agreed, let's rather not.
> >
> >> In this case an enduser might plug in a bad monitor or TV and be unable
> >> to play protected content.
> >>
> >> What if we add a new enum value to the content_type property that says
> >> "DRM_MODE_HDCP_CONTENT_TYPE_FORCE_14"?
> >
> > In general, I think if the fix is to teach the user to jump through
> > hoops in case the output is not working, it is really not a fix.
> >
> > Would, say, a set top box or a Blu-ray player have a setting to force
> > HDCP 1.4, and a troubleshooting item in the manual to select that if the
> > display does not work? Or would OS X have that?
> >
>
> Not sure. AFAIU on other OS we're currently dealing with this through
> monitor quirks. We can probably pull the same quirks to DRM.
>
> > If broken HDCP 2.2 sink support is a widespread problem (is it?), what
> > do other HDCP sources do? If it's a Linux issue, what are we doing wrong
> > or different?
>
> Not a Linux issue and not overly widespread. Looks like a handful of
> receivers are problematic.

Could we just mass-import that quirk list (since it seems it's not
unreasonable big) and be done with this?
-Daniel

> Harry
>
> >
> >
> > BR,
> > Jani.
> >
> >
> >
> >>
> >> Harry
> >>
> >>> In case if you want to track and implement a quirk for it, like not to
> >>> project the HDCP2.2 capability, you can use the receiver id of that panel
> >>> to track it.
> >>>
> >>> Thanks,
> >>> -Ram
> >>>>
> >>>>
> >>>> Thanks,
> >>>>
> >>>> Bhawan
> >> _______________________________________________
> >> dri-devel mailing list
> >> dri-devel@lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> >



-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel