On Thu, 13 Feb 2025, Suraj Kandpal <suraj.kand...@intel.com> wrote:
> Testing HDCP 1.4 becomes tough since the only way our code comes to
> HDCP 1.4 pathway is if the monitor only supports HDCP 1.4 which
> becomes tough to find sometimes.
> Setting this debug_fs entry will force use to use the HDCP 1.4 path
> so that more robust HDCP 1.4 testing can take place.
>
> --v2
> -Move the code to intel_hdcp.c [Jani]
> -Remove useless debug logging [Jani]
That's still there.
BR,
Jani.
> -Remove Force_HDCP from the debug file [Jani]
>
> Signed-off-by: Suraj Kandpal <suraj.kand...@intel.com>
> ---
> .../drm/i915/display/intel_display_types.h | 2 +
> drivers/gpu/drm/i915/display/intel_hdcp.c | 79 ++++++++++++++++++-
> 2 files changed, 80 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 6a82c6ade549..c78dd77ef74c 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -496,6 +496,8 @@ struct intel_hdcp {
> enum transcoder cpu_transcoder;
> /* Only used for DP MST stream encryption */
> enum transcoder stream_transcoder;
> + /* Used to force HDCP 1.4 bypassing HDCP 2.x */
> + bool force_hdcp14;
> };
>
> struct intel_connector {
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c
> b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index 1aa4c0fd216f..bbf553205c7d 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -2472,13 +2472,16 @@ static int _intel_hdcp_enable(struct
> intel_atomic_state *state,
> * Considering that HDCP2.2 is more secure than HDCP1.4, If the setup
> * is capable of HDCP2.2, it is preferred to use HDCP2.2.
> */
> - if (intel_hdcp2_get_capability(connector)) {
> + if (!hdcp->force_hdcp14 && intel_hdcp2_get_capability(connector)) {
> ret = _intel_hdcp2_enable(state, connector);
> if (!ret)
> check_link_interval =
> DRM_HDCP2_CHECK_PERIOD_MS;
> }
>
> + if (hdcp->force_hdcp14)
> + drm_dbg_kms(display->drm, "Forcing HDCP 1.4\n");
> +
> /*
> * When HDCP2.2 fails and Content Type is not Type1, HDCP1.4 will
> * be attempted.
> @@ -2797,6 +2800,78 @@ static int intel_hdcp_sink_capability_show(struct
> seq_file *m, void *data)
> }
> DEFINE_SHOW_ATTRIBUTE(intel_hdcp_sink_capability);
>
> +static ssize_t intel_hdcp_force_14_write(struct file *file,
> + const char __user *ubuf,
> + size_t len, loff_t *offp)
> +{
> + struct seq_file *m = file->private_data;
> + struct intel_connector *connector = m->private;
> + struct intel_display *display = to_intel_display(connector);
> + struct intel_hdcp *hdcp = &connector->hdcp;
> + bool force_hdcp14 = false;
> + int ret;
> +
> + if (len == 0)
> + return 0;
> +
> + drm_dbg(display->drm,
> + "Copied %zu bytes from user to force DSC\n", len);
> +
> + ret = kstrtobool_from_user(ubuf, len, &force_hdcp14);
> + if (ret < 0)
> + return ret;
> +
> + hdcp->force_hdcp14 = force_hdcp14;
> +
> + *offp += len;
> + return len;
> +}
> +
> +static int intel_hdcp_force_14_show(struct seq_file *m, void *data)
> +{
> + struct intel_connector *connector = m->private;
> + struct intel_display *display = to_intel_display(connector);
> + struct intel_encoder *encoder = intel_attached_encoder(connector);
> + struct intel_hdcp *hdcp = &connector->hdcp;
> + struct drm_crtc *crtc;
> + int ret;
> +
> + if (!encoder)
> + return -ENODEV;
> +
> + ret =
> drm_modeset_lock_single_interruptible(&display->drm->mode_config.connection_mutex);
> + if (ret)
> + return ret;
> +
> + crtc = connector->base.state->crtc;
> + if (connector->base.status != connector_status_connected || !crtc) {
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + seq_printf(m, "%s\n",
> + str_yes_no(hdcp->force_hdcp14));
> +out:
> + drm_modeset_unlock(&display->drm->mode_config.connection_mutex);
> + return ret;
> +}
> +
> +static int intel_hdcp_force_14_open(struct inode *inode,
> + struct file *file)
> +{
> + return single_open(file, intel_hdcp_force_14_show,
> + inode->i_private);
> +}
> +
> +static const struct file_operations intel_hdcp_force_14_fops = {
> + .owner = THIS_MODULE,
> + .open = intel_hdcp_force_14_open,
> + .read = seq_read,
> + .llseek = seq_lseek,
> + .release = single_release,
> + .write = intel_hdcp_force_14_write
> +};
> +
> void intel_hdcp_connector_debugfs_add(struct intel_connector *connector)
> {
> struct dentry *root = connector->base.debugfs_entry;
> @@ -2807,5 +2882,7 @@ void intel_hdcp_connector_debugfs_add(struct
> intel_connector *connector)
> connector_type == DRM_MODE_CONNECTOR_HDMIB) {
> debugfs_create_file("i915_hdcp_sink_capability", 0444, root,
> connector,
> &intel_hdcp_sink_capability_fops);
> + debugfs_create_file("i915_force_hdcp14", 0644, root,
> + connector, &intel_hdcp_force_14_fops);
> }
> }
--
Jani Nikula, Intel
