RE: [PATCH 06/10] drm/i915/xe3lpd: Add macro to choose HDCP_LINE_REKEY bit

[Jani Nikula <jani.nikula@linux.intel.com>]

On Thu, 10 Oct 2024, "Kandpal, Suraj" <suraj.kandpal@intel.com> wrote:
>> -----Original Message-----
>> From: Jani Nikula <jani.nikula@linux.intel.com>
>> Sent: Wednesday, October 9, 2024 1:09 PM
>> To: Atwood, Matthew S <matthew.s.atwood@intel.com>; intel-
>> xe@lists.freedesktop.org; intel-gfx@lists.freedesktop.org
>> Cc: Kandpal, Suraj <suraj.kandpal@intel.com>; Atwood, Matthew S
>> <matthew.s.atwood@intel.com>
>> Subject: Re: [PATCH 06/10] drm/i915/xe3lpd: Add macro to choose
>> HDCP_LINE_REKEY bit
>> 
>> On Tue, 08 Oct 2024, Matt Atwood <matthew.s.atwood@intel.com> wrote:
>> > From: Suraj Kandpal <suraj.kandpal@intel.com>
>> >
>> > DISPLAY_VER() >= 30 has the HDCP_LINE_REKEY bit redefined from bit 12
>> > to bit 14. Create a macro to choose the correct bit based on
>> > DISPLAY_VER().
>> >
>> > Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
>> > Signed-off-by: Matt Atwood <matthew.s.atwood@intel.com>
>> > ---
>> >  drivers/gpu/drm/i915/display/intel_hdcp.c | 5 +++--
>> >  drivers/gpu/drm/i915/i915_reg.h           | 2 +-
>> >  2 files changed, 4 insertions(+), 3 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c
>> > b/drivers/gpu/drm/i915/display/intel_hdcp.c
>> > index ed6aa87403e2..e9b0414590ce 100644
>> > --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
>> > +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
>> > @@ -47,10 +47,11 @@ intel_hdcp_disable_hdcp_line_rekeying(struct
>> intel_encoder *encoder,
>> >  			intel_de_rmw(display, MTL_CHICKEN_TRANS(hdcp-
>> >cpu_transcoder),
>> >  				     0, HDCP_LINE_REKEY_DISABLE);
>> >  		else if (IS_DISPLAY_VER_STEP(display, IP_VER(14, 1), STEP_B0,
>> STEP_FOREVER) ||
>> > -			 IS_DISPLAY_VER_STEP(display, IP_VER(20, 0),
>> STEP_B0, STEP_FOREVER))
>> > +			 IS_DISPLAY_VER_STEP(display, IP_VER(20, 0),
>> STEP_B0, STEP_FOREVER) ||
>> > +			 DISPLAY_VER(display) >= 30)
>> >  			intel_de_rmw(display,
>> >  				     TRANS_DDI_FUNC_CTL(display, hdcp-
>> >cpu_transcoder),
>> > -				     0,
>> TRANS_DDI_HDCP_LINE_REKEY_DISABLE);
>> > +				     0,
>> TRANS_DDI_HDCP_LINE_REKEY_DISABLE(display));
>> >  	}
>> >  }
>> >
>> > diff --git a/drivers/gpu/drm/i915/i915_reg.h
>> > b/drivers/gpu/drm/i915/i915_reg.h index d30459f8d1cb..da65500cd0c8
>> > 100644
>> > --- a/drivers/gpu/drm/i915/i915_reg.h
>> > +++ b/drivers/gpu/drm/i915/i915_reg.h
>> > @@ -3832,7 +3832,7 @@ 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_HDCP_LINE_REKEY_DISABLE(display)
>> 	(DISPLAY_VER(display) >= 30 ? REG_BIT(15) : REG_BIT(12))
>> 
>> Do we really want to extend this style to individual bits?
>
> I just thought this might be cleaner should we use 
> TRANS_DDI_HDCP_LINE_REKEY_DISABLE
> And 
> XE3_TRANS_DDI_HDCP_LINE_REKEY_DISABLE instead then?

I think so yes.

If it becomes too ugly in code, at the very least define the bits
separately instead of inline in the ternary operator.

BR,
Jani.


>
> Regards,
> Suraj Kandpal
>
>> 
>> BR,
>> Jani.
>> 
>> >  #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)
>> 
>> --
>> Jani Nikula, Intel

-- 
Jani Nikula, Intel