I'm not terribly familiar with HDCP, but from reading the spec my understanding is that in general we need to enable rekeying for HDCP 1.4 and disable it for higher HDCP versions, right? That would be the expected "normal" programming for all platforms if we didn't have any workarounds. However the issue here is that we have a workaround (Wa_16021352814) which affects the early steppings of certain platforms and instructs us to "Prune timings with hblank below 138" instead of disabling rekeying. In that case, I'd expect the logic for this function to be something like the following pseudocode: needs_wa_16021352814() { return IS_DISPLAY_STEP(IP_VER(14, 0), STEP_A0, STEP_D0) || IS_DISPLAY_STEP(IP_VER(14, 1), STEP_A0, STEP_B0) || IS_DISPLAY_STEP(IP_VER(20, 0), STEP_A0, STEP_B0); } intel_hdcp_disable_hdcp_line_rekeying() { assert(output is HDMI); assert(HDCP > 1.4); /* * Wa_16021352814: Rather than disabling rekeying, we need * to prune timings with hblank below 138 pixels, which is * taken care of in xxxxxx(). */ if (needs_wa_16021352814()) return; if (DISPLAY_VER_FULL() >= IP_VER(14, 1)) intel_de_rmw(TRANS_DDI_FUNC_CTL, ...); else intel_de_rmw(MTL_CHICKEN_TRANS, ...); } And the logic to prune modes according to hblank for this workaround would need to be programmed somewhere as well...has that already happened? Matt On Mon, May 27, 2024 at 10:51:19AM +0530, Suraj Kandpal wrote: > Replace IS_METEORLAKE usage with a more appropriate macro. While > we are at it also add the stepping restrictions for other platforms. > > Fixes: 6a3691ca4799 ("drm/i915/hdcp: Disable HDCP Line Rekeying for HDCP2.2 on HDMI") > Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx> > --- > drivers/gpu/drm/i915/display/intel_hdcp.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c > index 02cbbbfd8e25..5767070248bb 100644 > --- a/drivers/gpu/drm/i915/display/intel_hdcp.c > +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c > @@ -42,10 +42,11 @@ intel_hdcp_disable_hdcp_line_rekeying(struct intel_encoder *encoder, > return; > > if (DISPLAY_VER(dev_priv) >= 14) { > - if (IS_METEORLAKE(dev_priv)) > + if (IS_DISPLAY_IP_STEP(dev_priv, IP_VER(14, 0), STEP_D0, STEP_FOREVER)) > intel_de_rmw(dev_priv, MTL_CHICKEN_TRANS(hdcp->cpu_transcoder), > 0, HDCP_LINE_REKEY_DISABLE); > - else > + else if (IS_DISPLAY_IP_STEP(dev_priv, IP_VER(14, 1), STEP_B0, STEP_FOREVER) || > + IS_DISPLAY_IP_STEP(dev_priv, IP_VER(20, 0), STEP_B0, STEP_FOREVER)) > intel_de_rmw(dev_priv, TRANS_DDI_FUNC_CTL(hdcp->cpu_transcoder), > 0, TRANS_DDI_HDCP_LINE_REKEY_DISABLE); > } > -- > 2.43.2 > -- Matt Roper Graphics Software Engineer Linux GPU Platform Enablement Intel Corporation