Re: [PATCH v4 0/9] drm/i915: Implement HDCP

[Jose Abreu]

Hi Sean,

On 07-12-2017 00:00, Sean Paul wrote:
> Welcome to version 4 of the patchset. I think we're nearing the finish line
> (hopefully) now. This set addresses the review feedback from v3. I applied some
> R-b's from v3 review, and converted others to Cc since other changes were made
> to the patch, and I didn't want to speak for reviewers.
>
> Thanks for all the review feedback!

Thanks for your patches, nice to see HDCP patches making it into DRM!

I'm not familiar with i915 driver/hw but I do am familiar with
HDCP for HDMI. Here goes a few notes:
- You should make sure that you are streaming valid TMDS data
after reading the BKSV. I think by spec you can read BKSV at any
point but the remaining operations need to be done *after* you
start sending video, otherwise you can end up with wrong Ri's
because Ri rotation is done using TMDS clock...
- Also according to spec you should make sure BSTATUS reports DVI
state in first read (i.e. before start sending video) and that
HDMI_RESERVED field is tied to one.
- I think you should clearly indicate that this is for HDCP 1.4
because HDCP 2.2 is a lot different.

Also, is there any possibility to port any of these functions for
main DRM core? I mean, not the shim ops which seem very specific
for your HW, but at least a .enable, .disable, .link_check
callbacks would be useful to help others to also implement HDCP ...

Best Regards,
Jose Miguel Abreu

>
> Sean
>
> Sean Paul (9):
>   drm: Fix link-status kerneldoc line lengths
>   drm/i915: Add more control to wait_for routines
>   drm: Add Content Protection property
>   drm: Add some HDCP related #defines
>   drm/i915: Add HDCP framework + base implementation
>   drm/i915: Make use of indexed write GMBUS feature
>   drm/i915: Add function to output Aksv over GMBUS
>   drm/i915: Implement HDCP for HDMI
>   drm/i915: Implement HDCP for DisplayPort
>
>  drivers/gpu/drm/drm_atomic.c         |   8 +
>  drivers/gpu/drm/drm_connector.c      |  87 ++++-
>  drivers/gpu/drm/drm_sysfs.c          |   1 +
>  drivers/gpu/drm/i915/Makefile        |   1 +
>  drivers/gpu/drm/i915/i915_drv.h      |   1 +
>  drivers/gpu/drm/i915/i915_reg.h      |  85 ++++
>  drivers/gpu/drm/i915/intel_atomic.c  |   2 +
>  drivers/gpu/drm/i915/intel_ddi.c     |  36 ++
>  drivers/gpu/drm/i915/intel_display.c |   4 +
>  drivers/gpu/drm/i915/intel_dp.c      | 244 +++++++++++-
>  drivers/gpu/drm/i915/intel_drv.h     | 106 ++++-
>  drivers/gpu/drm/i915/intel_hdcp.c    | 735 +++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_hdmi.c    | 250 ++++++++++++
>  drivers/gpu/drm/i915/intel_i2c.c     |  81 +++-
>  drivers/gpu/drm/i915/intel_uncore.c  |  23 +-
>  drivers/gpu/drm/i915/intel_uncore.h  |  14 +-
>  include/drm/drm_connector.h          |  16 +
>  include/drm/drm_dp_helper.h          |  17 +
>  include/drm/drm_hdcp.h               |  56 +++
>  include/uapi/drm/drm_mode.h          |   4 +
>  20 files changed, 1728 insertions(+), 43 deletions(-)
>  create mode 100644 drivers/gpu/drm/i915/intel_hdcp.c
>  create mode 100644 include/drm/drm_hdcp.h
>