[Intel-gfx] [PATCH 13/15] drm/i915: don't save/restore PCH_LVDS on LPT

[Daniel Vetter]

On Fri, Mar 15, 2013 at 02:04:22PM -0700, Ben Widawsky wrote:
> On Wed, Mar 06, 2013 at 08:03:20PM -0300, Paulo Zanoni wrote:
> > From: Paulo Zanoni <paulo.r.zanoni at intel.com>
> > 
> > Because the register does not exist on LPT. The interesting fact is
> > that reading/writing PCH_LVDS on LPT does *not* give us "unclaimed
> > register" messages, but the register value is always 0.
> > 
> > Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_suspend.c |    7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
> > index c1e02b0..41f0fde 100644
> > --- a/drivers/gpu/drm/i915/i915_suspend.c
> > +++ b/drivers/gpu/drm/i915/i915_suspend.c
> > @@ -209,7 +209,8 @@ static void i915_save_display(struct drm_device *dev)
> >  		dev_priv->regfile.saveBLC_PWM_CTL2 = I915_READ(BLC_PWM_PCH_CTL2);
> >  		dev_priv->regfile.saveBLC_CPU_PWM_CTL = I915_READ(BLC_PWM_CPU_CTL);
> >  		dev_priv->regfile.saveBLC_CPU_PWM_CTL2 = I915_READ(BLC_PWM_CPU_CTL2);
> > -		dev_priv->regfile.saveLVDS = I915_READ(PCH_LVDS);
> > +		if (HAS_PCH_IBX(dev) || HAS_PCH_CPT(dev))
> > +			dev_priv->regfile.saveLVDS = I915_READ(PCH_LVDS);
> >  	} else {
> >  		dev_priv->regfile.savePP_CONTROL = I915_READ(PP_CONTROL);
> >  		dev_priv->regfile.savePFIT_PGM_RATIOS = I915_READ(PFIT_PGM_RATIOS);
> > @@ -271,9 +272,9 @@ static void i915_restore_display(struct drm_device *dev)
> >  	if (drm_core_check_feature(dev, DRIVER_MODESET))
> >  		mask = ~LVDS_PORT_EN;
> >  
> > -	if (HAS_PCH_SPLIT(dev)) {
> > +	if (HAS_PCH_IBX(dev) || HAS_PCH_CPT(dev))
> >  		I915_WRITE(PCH_LVDS, dev_priv->regfile.saveLVDS & mask);
> > -	} else if (IS_MOBILE(dev) && !IS_I830(dev))
> > +	else if (INTEL_INFO(dev)->gen <= 4 && IS_MOBILE(dev) && !IS_I830(dev))
> >  		I915_WRITE(LVDS, dev_priv->regfile.saveLVDS & mask);
> >  
> >  	if (!IS_I830(dev) && !IS_845G(dev) && !HAS_PCH_SPLIT(dev))
> 
> We don't support UMS on gen6+ so yuo can probably just check IS_GEN5
> instead of if (HAS_PCH_IBX(dev) || HAS_PCH_CPT(dev))

Hah, trapped! We need to restore the LVDS reg even on kms safe for bit31
(which would enable the panel port) since we don't track all the bits of
the panel state. And the bios doesn't really restore that ...

Queued for -next, thanks for the patch.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch