On Mon, Apr 02, 2018 at 02:35:42PM +0530, Ramalingam C wrote:
> 
> 
> On Thursday 29 March 2018 07:54 PM, Ville Syrjälä wrote:
> > On Thu, Mar 29, 2018 at 07:39:07PM +0530, Ramalingam C wrote:
> >> HDCP1.4 key can be loaded, only when Power well #1 is enabled and cdclk
> >> is enabled. Using the I915 power well infrastruture, above requirement
> >> is verified.
> >>
> >> This patch enables the hdcp initialization for HSW, BDW, and BXT.
> >>
> >> v2:
> >>    Choose the PW# based on the platform.
> >>
> >> Signed-off-by: Ramalingam C <ramalinga...@intel.com>
> >> Reviewed-by: Sean Paul <seanp...@chromium.org>
> >> ---
> >>   drivers/gpu/drm/i915/intel_hdcp.c | 41 
> >> +++++++++++++++++++++++++++++++++++++--
> >>   1 file changed, 39 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/intel_hdcp.c 
> >> b/drivers/gpu/drm/i915/intel_hdcp.c
> >> index f77d956b2b18..d8af09b46a44 100644
> >> --- a/drivers/gpu/drm/i915/intel_hdcp.c
> >> +++ b/drivers/gpu/drm/i915/intel_hdcp.c
> >> @@ -37,6 +37,43 @@ static int intel_hdcp_poll_ksv_fifo(struct 
> >> intel_digital_port *intel_dig_port,
> >>    return 0;
> >>   }
> >>   
> >> +static bool hdcp_key_loadable(struct drm_i915_private *dev_priv)
> >> +{
> >> +  struct i915_power_domains *power_domains = &dev_priv->power_domains;
> >> +  struct i915_power_well *power_well;
> >> +  enum i915_power_well_id id;
> >> +  bool enabled = false;
> >> +
> >> +  /*
> >> +   * On HSW and BDW, Display HW loads the Key as soon as Display resumes.
> >> +   * On all BXT+, SW can load the keys only when the PW#1 is turned on.
> >> +   */
> >> +  if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
> >> +          id = HSW_DISP_PW_GLOBAL;
> >> +  else
> >> +          id = SKL_DISP_PW_1;
> >> +
> >> +  mutex_lock(&power_domains->lock);
> >> +
> >> +  /* PG1 (power well #1) needs to be enabled */
> >> +  for_each_power_well(dev_priv, power_well) {
> >> +          if (power_well->id == id) {
> >> +                  enabled = power_well->ops->is_enabled(dev_priv,
> >> +                                                        power_well);
> >> +                  break;
> >> +          }
> >> +  }
> >> +  mutex_unlock(&power_domains->lock);
> >> +
> >> +  /*
> >> +   * Another req for hdcp key loadability is enabled state of pll for
> >> +   * cdclk. Without active crtc we wont land here. So we are assuming that
> >> +   * cdclk is already on.
> >> +   */
> >> +
> >> +  return enabled;
> >> +}
> >> +
> >>   static void intel_hdcp_clear_keys(struct drm_i915_private *dev_priv)
> >>   {
> >>    I915_WRITE(HDCP_KEY_CONF, HDCP_CLEAR_KEYS_TRIGGER);
> >> @@ -615,8 +652,8 @@ static int _intel_hdcp_enable(struct intel_connector 
> >> *connector)
> >>    DRM_DEBUG_KMS("[%s:%d] HDCP is being enabled...\n",
> >>                  connector->base.name, connector->base.base.id);
> >>   
> >> -  if (!(I915_READ(SKL_FUSE_STATUS) & SKL_FUSE_PG_DIST_STATUS(1))) {
> >> -          DRM_ERROR("PG1 is disabled, cannot load keys\n");
> >> +  if (!hdcp_key_loadable(dev_priv)) {
> >> +          DRM_ERROR("HDCP key Load is not possible\n");
> >>            return -ENXIO;
> >>    }
> > If you need the power well then why aren't you grabbing the correct
> > power domain reference somewhere?
> 
> Ville,
> 
> As HDCP is supposed to be enabled after the basic display is up, power well 
> #1 is supposed to be enabled.
> If not that is mostly an error w.r.t HDCP.
> 
> So at this point we just want to verify whether required PW is up and HDCP 
> key can be loaded from the HW. Else fail the HDCP request.

So this is in practice dead code to deal with a hypothetical bug
elsewhere in the driver?

-- 
Ville Syrjälä
Intel OTC
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Reply via email to