[PATCH] drm/i915/hdcp: Disable HDCP Line Rekeying for HDCP2.2 on HDMI

[Borah, Chaitanya Kumar]

> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Suraj
> Kandpal
> Sent: Tuesday, May 7, 2024 11:53 AM
> To: intel-gfx at lists.freedesktop.org
> Cc: Manna, Animesh <animesh.manna at intel.com>; Kandpal, Suraj
> <suraj.kandpal at intel.com>
> Subject: [PATCH] drm/i915/hdcp: Disable HDCP Line Rekeying for HDCP2.2 on
> HDMI
> 
> Disable HDCP Line Rekeying when HDCP ver > 1.4 and when we are on HDMI
> TMDS operation for DISPLAY_VER >= 14.
> 
> --v2
> -Wa to be mentioned in comments not in commit message [Jani] -Remove
> blankline [Jani]
> 
> --v3
> -No need to write what is being done in comments when code is self
> explanatory [Jani]
> 
> --v4
> -Add comment regarding need of this WA when in TMDS mode [Chaitanya] -
> Write in chicken register for MTL [CHaitanya]
> 
> --v5
> -Fix comment [Chaitanya]
> -Use correct set and clear value in intel_de_rmw [Chaitanya]
> 
> --v6
> -No need to define C, D chicken bits it gets calculated [Animesh]
> 
> Bspec: 49273
> Bspec: 69964

LGTM,
Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah at intel.com>

> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_hdcp.c | 23 +++++++++++++++++++++++
>  drivers/gpu/drm/i915/i915_reg.h           |  2 ++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c
> b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index d5ed4c7dfbc0..02cbbbfd8e25 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -30,6 +30,27 @@
>  #define KEY_LOAD_TRIES	5
>  #define HDCP2_LC_RETRY_CNT			3
> 
> +/* WA: 16022217614 */
> +static void
> +intel_hdcp_disable_hdcp_line_rekeying(struct intel_encoder *encoder,
> +				      struct intel_hdcp *hdcp)
> +{
> +	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> +
> +	/* Here we assume HDMI is in TMDS mode of operation */
> +	if (encoder->type != INTEL_OUTPUT_HDMI)
> +		return;
> +
> +	if (DISPLAY_VER(dev_priv) >= 14) {
> +		if (IS_METEORLAKE(dev_priv))
> +			intel_de_rmw(dev_priv, MTL_CHICKEN_TRANS(hdcp-
> >cpu_transcoder),
> +				     0, HDCP_LINE_REKEY_DISABLE);
> +		else
> +			intel_de_rmw(dev_priv, TRANS_DDI_FUNC_CTL(hdcp-
> >cpu_transcoder),
> +				     0,
> TRANS_DDI_HDCP_LINE_REKEY_DISABLE);
> +	}
> +}
> +
>  static int intel_conn_to_vcpi(struct intel_atomic_state *state,
>  			      struct intel_connector *connector)  { @@ -2005,6
> +2026,8 @@ static int _intel_hdcp2_enable(struct intel_atomic_state *state,
>  		    connector->base.base.id, connector->base.name,
>  		    hdcp->content_type);
> 
> +	intel_hdcp_disable_hdcp_line_rekeying(connector->encoder, hdcp);
> +
>  	ret = hdcp2_authenticate_and_encrypt(state, connector);
>  	if (ret) {
>  		drm_dbg_kms(&i915->drm, "HDCP2 Type%d  Enabling Failed.
> (%d)\n", diff --git a/drivers/gpu/drm/i915/i915_reg.h
> b/drivers/gpu/drm/i915/i915_reg.h index ae692f461982..9f2171f0adf8
> 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -3520,6 +3520,7 @@
>  #define   DP_FEC_BS_JITTER_WA		REG_BIT(15)
>  #define   PSR2_VSC_ENABLE_PROG_HEADER	REG_BIT(12)
>  #define   DP_DSC_INSERT_SF_AT_EOL_WA	REG_BIT(4)
> +#define   HDCP_LINE_REKEY_DISABLE	REG_BIT(0)
> 
>  #define DISP_ARB_CTL	_MMIO(0x45000)
>  #define   DISP_FBC_MEMORY_WAKE		REG_BIT(31)
> @@ -4521,6 +4522,7 @@ enum skl_power_gate {
>  #define  TRANS_DDI_EDP_INPUT_B_ONOFF	(5 << 12)
>  #define  TRANS_DDI_EDP_INPUT_C_ONOFF	(6 << 12)
>  #define  TRANS_DDI_EDP_INPUT_D_ONOFF	(7 << 12)
> +#define  TRANS_DDI_HDCP_LINE_REKEY_DISABLE	REG_BIT(12)
>  #define  TRANS_DDI_MST_TRANSPORT_SELECT_MASK	REG_GENMASK(11,
> 10)
>  #define  TRANS_DDI_MST_TRANSPORT_SELECT(trans)	\
>  	REG_FIELD_PREP(TRANS_DDI_MST_TRANSPORT_SELECT_MASK,
> trans)
> --
> 2.43.2