On Wed, 06 Nov 2024, Suraj Kandpal <suraj.kandpal@xxxxxxxxx> wrote:
> TRANS_DDI_FUNC_CTL asks us to disable hdcp line rekeying when not in
> hdcp 2.2 and we are not using an hdmi transcoder and it need to be
> enabled when we are using an HDMI transcoder to enable HDCP 1.4.
> We use intel_de_rmw cycles to update TRANS_DDI_FUNC_CTL register so
> we cannot depend on the value being 0 by default everytime which calls
> for seprate handling of HDCP 1.4 case.
>
> --v2
> -Use the exising function and modify it based on a bool rather than
> have a different function [Matt]
>
> --v3
> -No need for kzalloc [Jani]
The code still needs to make sense! You can't just remove allocation and
use whatever stack garbage rekey_reg happens to point at. Look at all
the other code that uses i915_reg_t. You can't possibly assume I
would've needed to say "it shouldn't be a pointer at all"?
BR,
Jani.
>
> Bspec: 69964, 50493, 50054
> Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_hdcp.c | 36 +++++++++++++----------
> 1 file changed, 21 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index 4e937fbba4d2..6ad5efc9711c 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -32,27 +32,31 @@
> #define HDCP2_LC_RETRY_CNT 3
>
> static void
> -intel_hdcp_disable_hdcp_line_rekeying(struct intel_encoder *encoder,
> - struct intel_hdcp *hdcp)
> +intel_hdcp_adjust_hdcp_line_rekeying(struct intel_encoder *encoder,
> + struct intel_hdcp *hdcp,
> + bool enable)
> {
> struct intel_display *display = to_intel_display(encoder);
> + i915_reg_t *rekey_reg;
> + u32 rekey_bit;
>
> /* Here we assume HDMI is in TMDS mode of operation */
> if (encoder->type != INTEL_OUTPUT_HDMI)
> return;
>
> - if (DISPLAY_VER(display) >= 30)
> - intel_de_rmw(display,
> - TRANS_DDI_FUNC_CTL(display, hdcp->cpu_transcoder),
> - 0, XE3_TRANS_DDI_HDCP_LINE_REKEY_DISABLE);
> - else if (IS_DISPLAY_VERx100_STEP(display, 1401, STEP_B0, STEP_FOREVER) ||
> - IS_DISPLAY_VERx100_STEP(display, 2000, STEP_B0, STEP_FOREVER))
> - intel_de_rmw(display,
> - TRANS_DDI_FUNC_CTL(display, hdcp->cpu_transcoder),
> - 0, TRANS_DDI_HDCP_LINE_REKEY_DISABLE);
> - else if (IS_DISPLAY_VERx100_STEP(display, 1400, STEP_D0, STEP_FOREVER))
> - intel_de_rmw(display, MTL_CHICKEN_TRANS(hdcp->cpu_transcoder),
> - 0, HDCP_LINE_REKEY_DISABLE);
> + if (DISPLAY_VER(display) >= 30) {
> + *rekey_reg = TRANS_DDI_FUNC_CTL(display, hdcp->cpu_transcoder);
> + rekey_bit = XE3_TRANS_DDI_HDCP_LINE_REKEY_DISABLE;
> + } else if (IS_DISPLAY_VERx100_STEP(display, 1401, STEP_B0, STEP_FOREVER) ||
> + IS_DISPLAY_VERx100_STEP(display, 2000, STEP_B0, STEP_FOREVER)) {
> + *rekey_reg = TRANS_DDI_FUNC_CTL(display, hdcp->cpu_transcoder);
> + rekey_bit = TRANS_DDI_HDCP_LINE_REKEY_DISABLE;
> + } else if (IS_DISPLAY_VERx100_STEP(display, 1400, STEP_D0, STEP_FOREVER)) {
> + *rekey_reg = MTL_CHICKEN_TRANS(hdcp->cpu_transcoder);
> + rekey_bit = HDCP_LINE_REKEY_DISABLE;
> + }
> +
> + intel_de_rmw(display, *rekey_reg, rekey_bit, enable ? 0 : rekey_bit);
> }
>
> static int intel_conn_to_vcpi(struct intel_atomic_state *state,
> @@ -1049,6 +1053,8 @@ static int intel_hdcp1_enable(struct intel_connector *connector)
> return ret;
> }
>
> + intel_hdcp_adjust_hdcp_line_rekeying(connector->encoder, hdcp, true);
> +
> /* Incase of authentication failures, HDCP spec expects reauth. */
> for (i = 0; i < tries; i++) {
> ret = intel_hdcp_auth(connector);
> @@ -2062,7 +2068,7 @@ 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);
> + intel_hdcp_adjust_hdcp_line_rekeying(connector->encoder, hdcp, false);
>
> ret = hdcp2_authenticate_and_encrypt(state, connector);
> if (ret) {
--
Jani Nikula, Intel
