[PATCH] drm/i915/display: Wait for PHY readiness not needed for disabling sequence

[Kahola, Mika]

> -----Original Message-----
> From: Deak, Imre <imre.deak at intel.com>
> Sent: Tuesday, December 12, 2023 12:08 PM
> To: Kahola, Mika <mika.kahola at intel.com>
> Cc: intel-gfx at lists.freedesktop.org
> Subject: Re: [PATCH] drm/i915/display: Wait for PHY readiness not needed for disabling sequence
> 
> On Tue, Dec 12, 2023 at 11:55:20AM +0200, Mika Kahola wrote:
> > When going through the disconnection flow we don't need to wait for
> > PHY readiness and hence we can skip the wait part. For disabling the
> > function returns false as an indicator that the power is not enabled.
> > After all, we are not even using the return value when Type-C is disconnecting.
> >
> > BSpec: 65380
> >
> > Signed-off-by: Mika Kahola <mika.kahola at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_tc.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_tc.c
> > b/drivers/gpu/drm/i915/display/intel_tc.c
> > index f64d348a969e..79ec17fa3edd 100644
> > --- a/drivers/gpu/drm/i915/display/intel_tc.c
> > +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> > @@ -1030,6 +1030,9 @@ static bool
> > xelpdp_tc_phy_enable_tcss_power(struct intel_tc_port *tc, bool enabl
> >
> >  	__xelpdp_tc_phy_enable_tcss_power(tc, enable);
> >
> > +	if (!enable)
> > +		return false;
> 
> Waiting for xelpdp_tc_phy_wait_for_tcss_power(tc, false); is also needed in the above case.

Ok. I would still keep this disabling part separate as if I combine this with existing if() the code looks a bit busy for me. 

Thanks!
Mika

> 
> > +
> >  	if ((!tc_phy_wait_for_ready(tc) ||
> >  	     !xelpdp_tc_phy_wait_for_tcss_power(tc, enable)) &&
> >  	    !drm_WARN_ON(&i915->drm, tc->mode == TC_PORT_LEGACY)) {
> > --
> > 2.34.1
> >