[Intel-gfx] [PATCH 10/16] drm/i915/bxt: Power down DDI PHYs separately during the per PHY uninit

[Imre Deak]

On pe, 2016-04-01 at 16:29 +0300, Jani Nikula wrote:
> On Fri, 01 Apr 2016, Imre Deak <imre.deak at intel.com> wrote:
> > The power-down step logically belongs to the individual PHY uninit
> > sequence so move it there. The only functional change is that we
> > will
> > power down now PHY 1 separately before PHY 0 and preserve the other
> > bits
> > in the register which are defined as reserved.
> > 
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_ddi.c | 7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_ddi.c
> > b/drivers/gpu/drm/i915/intel_ddi.c
> > index 29017a4..d16effd 100644
> > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > @@ -1849,15 +1849,16 @@ static void broxton_phy_uninit(struct
> > drm_i915_private *dev_priv,
> >  	val = I915_READ(BXT_PHY_CTL_FAMILY(phy));
> >  	val &= ~COMMON_RESET_DIS;
> >  	I915_WRITE(BXT_PHY_CTL_FAMILY(phy), val);
> > +
> > +	val = I915_READ(BXT_P_CR_GT_DISP_PWRON);
> > +	val &= ~GT_DISPLAY_POWER_ON(phy);
> > +	I915_WRITE(BXT_P_CR_GT_DISP_PWRON, val);
> >  }
> >  
> >  void broxton_ddi_phy_uninit(struct drm_i915_private *dev_priv)
> >  {
> >  	broxton_phy_uninit(dev_priv, DPIO_PHY1);
> >  	broxton_phy_uninit(dev_priv, DPIO_PHY0);
> 
> Unrelated to this patch, but since you're hashing stuff around
> here...
> 
> The init order is:
> 
> void broxton_ddi_phy_init(struct drm_device *dev)
> {
> 	/* Enable PHY1 first since it provides Rcomp for PHY0 */
> 	broxton_phy_init(dev->dev_private, DPIO_PHY1);
> 	broxton_phy_init(dev->dev_private, DPIO_PHY0);
> }
> 
> Should the uninit order be reversed?

That would be logical, but the bspec specifies this uninit order. The
init order is also fixed in the above way but it's understandable why.

--Imre