[PATCH] drm/xe/hdcp: Add check to remove hdcp2 compatibility

[Kandpal, Suraj]

> -----Original Message-----
> From: Ceraolo Spurio, Daniele <daniele.ceraolospurio at intel.com>
> Sent: Friday, October 25, 2024 8:35 PM
> To: Kandpal, Suraj <suraj.kandpal at intel.com>; intel-xe at lists.freedesktop.org;
> intel-gfx at lists.freedesktop.org
> Cc: Nautiyal, Ankit K <ankit.k.nautiyal at intel.com>; Ghimiray, Himal Prasad
> <himal.prasad.ghimiray at intel.com>
> Subject: Re: [PATCH] drm/xe/hdcp: Add check to remove hdcp2 compatibility
> 
> 
> 
> 
> On 10/24/2024 6:21 PM, Kandpal, Suraj wrote:
> >
> >> -----Original Message-----
> >> From: Ceraolo Spurio, Daniele <daniele.ceraolospurio at intel.com>
> >> Sent: Thursday, October 24, 2024 9:03 PM
> >> To: Kandpal, Suraj <suraj.kandpal at intel.com>;
> >> intel-xe at lists.freedesktop.org; intel-gfx at lists.freedesktop.org
> >> Cc: Nautiyal, Ankit K <ankit.k.nautiyal at intel.com>; Ghimiray, Himal
> >> Prasad <himal.prasad.ghimiray at intel.com>
> >> Subject: Re: [PATCH] drm/xe/hdcp: Add check to remove hdcp2
> >> compatibility
> >>
> >>
> >>
> >>
> >> On 10/22/2024 12:29 AM, Suraj Kandpal wrote:
> >>> Add check to remove HDCP2 compatibility from BMG as it does not have
> >>> GSC which ends up causing warning when we try to get reference of
> >>> GSC FW.
> >>>
> >>> Fixes: 89d030804831 ("drm/xe/hdcp: Fix condition for hdcp gsc cs
> >>> requirement")
> >>> Fixes: 883631771038 ("drm/i915/mtl: Add HDCP GSC interface")
> >>> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> >>> Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
> >>> Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
> >>> ---
> >>>    drivers/gpu/drm/i915/display/intel_hdcp_gsc.c | 3 ++-
> >>>    drivers/gpu/drm/xe/display/xe_hdcp_gsc.c      | 4 +++-
> >>>    2 files changed, 5 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c
> >>> b/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c
> >>> index 55965844d829..2c1d0ee8cec2 100644
> >>> --- a/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c
> >>> +++ b/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c
> >>> @@ -21,7 +21,8 @@ struct intel_hdcp_gsc_message {
> >>>
> >>>    bool intel_hdcp_gsc_cs_required(struct intel_display *display)
> >>>    {
> >>> -	return DISPLAY_VER(display) >= 14;
> >>> +	return DISPLAY_VER(display) >= 14 &&
> >>> +		DISPLAY_VER_FULL(display) != IP_VER(14, 1);
> >>>    }
> >>>
> >>>    bool intel_hdcp_gsc_check_status(struct intel_display *display)
> >>> diff --git a/drivers/gpu/drm/xe/display/xe_hdcp_gsc.c
> >>> b/drivers/gpu/drm/xe/display/xe_hdcp_gsc.c
> >>> index 231677129a35..efa3441c249c 100644
> >>> --- a/drivers/gpu/drm/xe/display/xe_hdcp_gsc.c
> >>> +++ b/drivers/gpu/drm/xe/display/xe_hdcp_gsc.c
> >>> @@ -8,6 +8,7 @@
> >>>    #include <linux/delay.h>
> >>>
> >>>    #include "abi/gsc_command_header_abi.h"
> >>> +#include "i915_drv.h"
> >>>    #include "intel_hdcp_gsc.h"
> >>>    #include "intel_hdcp_gsc_message.h"
> >>>    #include "xe_bo.h"
> >>> @@ -32,7 +33,8 @@ struct intel_hdcp_gsc_message {
> >>>
> >>>    bool intel_hdcp_gsc_cs_required(struct intel_display *display)
> >>>    {
> >>> -	return DISPLAY_VER(display) >= 14;
> >>> +	return DISPLAY_VER(display) >= 14 &&
> >>> +		DISPLAY_VER_FULL(display) != IP_VER(14, 1);
> >> I don't think this is the correct check or the correct location. BMG
> >> does require the GSC for HDCP, so intel_hdcp_gsc_cs_required() should
> >> still return true; it's just that we've decided not to support GSC FW
> >> loading on the platform, so we can't support HDCP2.x. Also note that
> >> the this might change and/or it might apply to other platform in the
> >> future, so any check needs to be done based on GSC support and not
> platform/display ID.
> >>
> >> IMO when intel_hdcp_gsc_cs_required() returns true, the caller should
> >> check if the GSC FW is defined (or if the GSCCS is available) and if
> >> it is not return that hdcp2 is not supported due to unmet
> >> prerequsites and fallback to 1.4 without printing any errors.
> >>
> > Here is the thing before this I thought that should have worked too
> > but after hdcp_gsc_cs_required() We call intel_hdcp_gsc_check_status()
> > which has the following check
> >
> > if (!gsc && !xe_uc_fw_is_enabled(&gsc->fw)) {
> 
> This check seems incorrect to me. Shouldn't it be an OR instead of an AND? It
> is an OR in the i915 code.

Yes this could be it will float a new version

Regards,
Suraj Kandpal

> 
> >                  drm_dbg_kms(&xe->drm,
> >                              "GSC Components not ready for HDCP2.x\n");
> >                  return false;
> >   }
> >
> > And this should have returned from here but it does not it goes ahead
> > and tries to get a xe_pm_runtime() Which causes it to shout out loud
> > which is currently causing a lot of noise in CI
> 
> See comment above about possible issue. But even if that is not the bug, if
> this function should return and it is not then we should fix this, not hack the
> intel_hdcp_gsc_cs_required() function.
> 
> Daniele
> 
> >
> > Regards,
> > Suraj Kandpal
> >
> >> Daniele
> >>
> >>>    }
> >>>
> >>>    bool intel_hdcp_gsc_check_status(struct intel_display *display)