[Intel-gfx] [PATCH v9 5/6] drm/i915/mtl: Add function to send command to GSC CS

[Teres Alexis, Alan Previn]

Conditional Rb with below fix in intel_hdcp_gsc_free_message:

Reviewed-by: Alan Previn <alan.previn.teres.alexis at intel.com>

On Tue, 2023-01-31 at 12:03 +0530, Kandpal, Suraj wrote:
> Add function that takes care of sending command to gsc cs. We start
> of with allocation of memory for our command intel_hdcp_gsc_message that
> contains gsc cs memory header as directed in specs followed by the
> actual payload hdcp message that we want to send.
> Spec states that we need to poll pending bit of response header around
> 20 times each try being 50ms apart hence adding that to current
> gsc_msg_send function
> Also we use the same function to take care of both sending and receiving
> hence no separate function to get the response.
> 
> 
alan:snip..

> +/*This function helps allocate memory for the command that we will send to gsc cs */
> +int intel_hdcp_gsc_hdcp2_init(struct drm_i915_private *i915)
> +{
> +
alan: okay i see this is now being called from intel_hdcp_gsc_init

> +void intel_hdcp_gsc_free_message(struct drm_i915_private *i915)
> +{
> +       struct intel_hdcp_gsc_message *hdcp_message =
> +                                       i915->display.hdcp.hdcp_message;
> +       if (hdcp_message->vma)
> +               i915_vma_unpin(fetch_and_zero(&hdcp_message->vma));
alan: i believe you don't need this extra i915_vma_unpin. Also, take note you have a bug above ...
first code does a "fetch_and_zero" and right after zero-ing out its used to call i915_vma_unpin_and_release
on the line below. So.. "if (hdcp_message->vma) -> i915_vma_unpin_and_release"
> +
> +       i915_vma_unpin_and_release(&hdcp_message->vma, I915_VMA_RELEASE_MAP);
> +       kfree(hdcp_message);
> +}
> +
> 

alan:snip..
> -- 
> 2.25.1
>