[PATCH v3 1/2] drm/i915/display: Add MTL subplatforms definition

[Bhadane, Dnyaneshwar]

> -----Original Message-----
> From: Jani Nikula <jani.nikula at linux.intel.com>
> Sent: Monday, December 16, 2024 4:48 PM
> To: Bhadane, Dnyaneshwar <dnyaneshwar.bhadane at intel.com>; intel-
> gfx at lists.freedesktop.org
> Cc: Bhadane, Dnyaneshwar <dnyaneshwar.bhadane at intel.com>
> Subject: Re: [PATCH v3 1/2] drm/i915/display: Add MTL subplatforms definition
> 
> On Fri, 13 Dec 2024, Dnyaneshwar Bhadane
> <dnyaneshwar.bhadane at intel.com> wrote:
> > Separate MTL-U platform PCI ids in one define macro.
> >
> > Add the MTL U/ARL U as subplatform member in MTL platform description
> > structure to use display.platform.<platform> from intel_display
> > structure instead of IS_<PLATFORM>() in display code path.
> >
> > Signed-off-by: Dnyaneshwar Bhadane <dnyaneshwar.bhadane at intel.com>
> > ---
> >  .../drm/i915/display/intel_display_device.c   | 21 +++++++++++++++++++
> >  .../drm/i915/display/intel_display_device.h   |  2 ++
> >  include/drm/intel/pciids.h                    |  5 ++++-
> >  3 files changed, 27 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c
> > b/drivers/gpu/drm/i915/display/intel_display_device.c
> > index 68cb7f9b9ef3..5dc689a8b1ae 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_device.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display_device.c
> > @@ -1357,6 +1357,16 @@ static const struct intel_display_device_info
> xe2_hpd_display = {
> >  		BIT(PORT_TC1) | BIT(PORT_TC2) | BIT(PORT_TC3) |
> BIT(PORT_TC4),  };
> >
> > +static const u16 arl_u_ids[] = {
> > +	INTEL_ARL_U_IDS(ID),
> > +	0
> > +};
> > +
> > +static const u16 mtl_u_ids[] = {
> > +	INTEL_MTL_U_IDS(ID),
> > +	0
> > +};
> 
> We don't have arrowlake platform definition. They're all just meteorlakes. Do
> you actually need the mtl-u/arl-u distinction, or do you just need mtl+arl vs.
> mtl-u+arl-u distinction?
Hi Jani, 
#1 No, don't need arl-u/mtl-u distinction then can be one-unit mtl-u+arl-u vs mtl+arl. 
I was trying to make readability on conditions to match with specs description. 
> 
> I.e. could we just have
> 
> static const u16 mtl_u_ids[] = {
> 	INTEL_MTL_U_IDS(ID),
> 	INTEL_ARL_U_IDS(ID),
> 	0
> };
> 
> And call them all mtl-u?
#2
Thank you, this suggestion looking good. 
For now, we don't need the arrowlake-u as separate and can be club with meteorlake-u.
I will follow this approach in next revision. 

but in future if we separate out arrowlake-u, then we should be careful to replace (arrowlake-u || meteorlake-u)
wherever needed.
> 
> > +
> >  /*
> >   * Do not initialize the .info member of the platform desc for GMD ID based
> >   * platforms. Their display will be probed automatically based on the
> > IP version @@ -1364,6 +1374,17 @@ static const struct
> intel_display_device_info xe2_hpd_display = {
> >   */
> >  static const struct platform_desc mtl_desc = {
> >  	PLATFORM(meteorlake),
> > +	.subplatforms = (const struct subplatform_desc[]) {
> > +		{
> > +			SUBPLATFORM(meteorlake, u),
> > +			.pciidlist = mtl_u_ids,
> > +		},
> > +		{
> > +			SUBPLATFORM(arrowlake, u),
> > +			.pciidlist = arl_u_ids,
> 
> You're defining subplatfroms for meteorlake. All the platform parameters for
> SUBPLATFORM() *must* match the PLATFORM() above.

> 
> > +		},
> > +		{},
> > +	}
> >  };
> >
> >  static const struct platform_desc lnl_desc = { diff --git
> > a/drivers/gpu/drm/i915/display/intel_display_device.h
> > b/drivers/gpu/drm/i915/display/intel_display_device.h
> > index 9a333d9e6601..87a614e2dfab 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_device.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display_device.h
> > @@ -96,6 +96,8 @@ struct pci_dev;
> >  	func(dg2_g12) \
> >  	/* Display ver 14 (based on GMD ID) */ \
> >  	func(meteorlake) \
> > +	func(meteorlake_u) \
> > +	func(arrowlake_u) \
> 
> The naming needs to be <platform>_<subplatform>. We don't have arrowlake
> platform, so we can't have arrowlake_u.
> 
> Either we can just put all mtl+arl u's together in meteorlake_u, or we define
> arl-u as meteorlake_arrowlake_u with meteorlake being the platform and
> arrowlake_u the subplatform.
This is good note to take for future, 
If they are very specific need of identifying arrowlake-u we should use this approach. 
For now, removing arrowlake_u and combining with meteorlake u subplatform as per comment #2.

Thank you, Jani

BR, 
Dnyaneshwar, 

>Jani
> 
> >  	/* Display ver 20 (based on GMD ID) */ \
> >  	func(lunarlake) \
> >  	/* Display ver 14.1 (based on GMD ID) */ \ diff --git
> > a/include/drm/intel/pciids.h b/include/drm/intel/pciids.h index
> > c6518b0992cf..f29034ccb36c 100644
> > --- a/include/drm/intel/pciids.h
> > +++ b/include/drm/intel/pciids.h
> > @@ -811,9 +811,12 @@
> >  	INTEL_ARL_S_IDS(MACRO__, ## __VA_ARGS__)
> >
> >  /* MTL */
> > +#define INTEL_MTL_U_IDS(MACRO__, ...) \
> > +	MACRO__(0x7D45, ## __VA_ARGS__)
> > +
> >  #define INTEL_MTL_IDS(MACRO__, ...) \
> >  	MACRO__(0x7D40, ## __VA_ARGS__), \
> > -	MACRO__(0x7D45, ## __VA_ARGS__), \
> > +	INTEL_MTL_U_IDS(MACRO__, ## __VA_ARGS__), \
> >  	MACRO__(0x7D55, ## __VA_ARGS__), \
> >  	MACRO__(0x7D60, ## __VA_ARGS__), \
> >  	MACRO__(0x7DD5, ## __VA_ARGS__)
> 
> --
> Jani Nikula, Intel