[Intel-gfx] [PATCH 2/4] drm/i915: II stage HDCP auth for repeater only

[Sean Paul]

On Thu, Jan 18, 2018 at 7:50 PM, C, Ramalingam <ramalingam.c at intel.com> wrote:
>> -----Original Message-----
>> From: Sean Paul [mailto:seanpaul at chromium.org]
>> Sent: Friday, January 19, 2018 3:54 AM
>> To: C, Ramalingam <ramalingam.c at intel.com>
>> Cc: intel-gfx at lists.freedesktop.org; seanpaul at chromium.org;
>> daniel.vetter at ffwll.ch; Vivi, Rodrigo <rodrigo.vivi at intel.com>; Sharma,
>> Shashank <shashank.sharma at intel.com>
>> Subject: Re: [PATCH 2/4] drm/i915: II stage HDCP auth for repeater only
>>
>> On Thu, Jan 18, 2018 at 11:18:06AM +0530, Ramalingam C wrote:
>> > Second stage of HDCP authentication required only if the HDCP sink is
>> > a repeater.
>> >
>> > This patch imposes above condition on second stage HDCP authentication.
>>
>> Hi Ram,
>> This is already enforced in intel_hdcp_auth_downstream()
>
> I am not able to locate any check for repeater capability at start of downstream auth.
>
> I am not sure whether you are referring to number of downstream device count check.
> That is valid after poll for ksv_fifo ready. We don't want to wait for 5Sec timeout in poll to detect the repeater cap.
>
> And since the caller is handy with the flag for repeater cap, it is best to decide on the call for downstream auth itself.
>

Thanks for clarifying, makes sense with the other patches in the set.

Sean

> Thanks
> --Ram
>>
>> Thanks,
>> Sean
>>
>> >
>> > Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
>> > ---
>> >  drivers/gpu/drm/i915/intel_hdcp.c | 5 ++++-
>> >  1 file changed, 4 insertions(+), 1 deletion(-)
>> >
>> > diff --git a/drivers/gpu/drm/i915/intel_hdcp.c
>> > b/drivers/gpu/drm/i915/intel_hdcp.c
>> > index 6ce6559897a6..b48c72cd0906 100644
>> > --- a/drivers/gpu/drm/i915/intel_hdcp.c
>> > +++ b/drivers/gpu/drm/i915/intel_hdcp.c
>> > @@ -493,7 +493,10 @@ static int intel_hdcp_auth(struct intel_digital_port
>> *intel_dig_port,
>> >      * on those as well.
>> >      */
>> >
>> > -   return intel_hdcp_auth_downstream(intel_dig_port, shim);
>> > +   if (repeater_present)
>> > +           return intel_hdcp_auth_downstream(intel_dig_port, shim);
>> > +
>> > +   return 0;
>> >  }
>> >
>> >  static
>> > --
>> > 2.7.4
>> >
>>
>> --
>> Sean Paul, Software Engineer, Google / Chromium OS