[Intel-gfx] [PATCH v3 04/23] drm/i915/bdw+: Enable PSR in any eDP port

[Runyan, Arthur J]

> -----Original Message-----
> From: Imre Deak <imre.deak at intel.com>
> Sent: Monday, 26 August, 2019 6:42 AM
> To: Souza, Jose <jose.souza at intel.com>; De Marchi, Lucas
> <lucas.demarchi at intel.com>; Runyan, Arthur J <arthur.j.runyan at intel.com>
> Cc: intel-gfx at lists.freedesktop.org; Pandiyan, Dhinakaran
> <dhinakaran.pandiyan at intel.com>
> Subject: Re: [Intel-gfx] [PATCH v3 04/23] drm/i915/bdw+: Enable PSR in any
> eDP port
> 
> On Fri, Aug 23, 2019 at 01:20:36AM -0700, Lucas De Marchi wrote:
> > From: José Roberto de Souza <jose.souza at intel.com>
> >
> > From BDW+ the PSR registers moved from DDIA to transcoder, so any port
> > with a eDP panel connected can have PSR, so lets remove this
> > limitation.
> >
> > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> > Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
> > Reviewed-by: Anshuman Gupta <anshuman.gupta at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_psr.c | 6 ++----
> >  1 file changed, 2 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> b/drivers/gpu/drm/i915/display/intel_psr.c
> > index 81e3619cd905..0172b82858d9 100644
> > --- a/drivers/gpu/drm/i915/display/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> > @@ -588,11 +588,9 @@ void intel_psr_compute_config(struct intel_dp
> *intel_dp,
> >
> >  	/*
> >  	 * HSW spec explicitly says PSR is tied to port A.
> > -	 * BDW+ platforms have a instance of PSR registers per transcoder but
> > -	 * for now it only supports one instance of PSR, so lets keep it
> > -	 * hardcoded to PORT_A
> > +	 * BDW+ platforms have a instance of PSR registers per transcoder.
> >  	 */
> > -	if (dig_port->base.port != PORT_A) {
> > +	if (IS_HASWELL(dev_priv) && dig_port->base.port != PORT_A) {
> 
> Based on an earlier discussion with Art, before TGL PSR is not supposed
> to be used anywhere else than port A.
> 
> Art could you confirm that?

Correct.  
PSR1 is limited to DDIA until Tigerlake.  There are registers for PSR on the other 
transcoders/ports because of reuse, but hardware isn't fully hooked up or validated.
PSR2 is still limited to DDIA on Tigerlake.

> 
> >  		DRM_DEBUG_KMS("PSR condition failed: Port not
> supported\n");
> >  		return;
> >  	}
> > --
> > 2.23.0
> >
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