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

[Souza, Jose]

On Tue, 2019-08-27 at 09:36 -0700, Lucas De Marchi wrote:
> On Mon, Aug 26, 2019 at 10:43:36AM -0700, Runyan, Arthur J wrote:
> > > -----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.
> 
> thank you both for confirming. José, I think we need to drop this
> patch
> and rebase the rest so we don't do anything before Tiger Lake. I will
> work on it.

Thanks, maybe write a patch updating the comment above would be nice.
Otherwise I can do it latter.

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