Re: [PATCH 14/40] drm/i915: Override display PHY TX FIFO reset master on chv

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Tue, Jul 29, 2014 at 09:57:09AM -0700, Jesse Barnes wrote:
> On Sat, 28 Jun 2014 02:04:05 +0300
> ville.syrjala@linux.intel.com wrote:
> 
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > Just an attempt to frob these bits. Apparently we should not need to
> > touch them (apart from maybe making sure the override is disabled so
> > that the hardware automagically does the right thing).
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_reg.h   | 12 ++++++++++++
> >  drivers/gpu/drm/i915/intel_dp.c   | 23 +++++++++++++++++++++++
> >  drivers/gpu/drm/i915/intel_hdmi.c | 23 +++++++++++++++++++++++
> >  3 files changed, 58 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 2a7bc22..d246609 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -758,6 +758,8 @@ enum punit_power_well {
> >  #define _VLV_PCS_DW0_CH1		0x8400
> >  #define   DPIO_PCS_TX_LANE2_RESET	(1<<16)
> >  #define   DPIO_PCS_TX_LANE1_RESET	(1<<7)
> > +#define   DPIO_LEFT_TXFIFO_RST_MASTER2	(1<<4)
> > +#define   DPIO_RIGHT_TXFIFO_RST_MASTER2	(1<<3)
> >  #define VLV_PCS_DW0(ch) _PORT(ch, _VLV_PCS_DW0_CH0, _VLV_PCS_DW0_CH1)
> >  
> >  #define _VLV_PCS01_DW0_CH0		0x200
> > @@ -834,8 +836,18 @@ enum punit_power_well {
> >  
> >  #define _VLV_PCS_DW11_CH0		0x822c
> >  #define _VLV_PCS_DW11_CH1		0x842c
> > +#define   DPIO_LANEDESKEW_STRAP_OVRD	(1<<3)
> > +#define   DPIO_LEFT_TXFIFO_RST_MASTER	(1<<1)
> > +#define   DPIO_RIGHT_TXFIFO_RST_MASTER	(1<<0)
> >  #define VLV_PCS_DW11(ch) _PORT(ch, _VLV_PCS_DW11_CH0, _VLV_PCS_DW11_CH1)
> >  
> > +#define _VLV_PCS01_DW11_CH0		0x022c
> > +#define _VLV_PCS23_DW11_CH0		0x042c
> > +#define _VLV_PCS01_DW11_CH1		0x262c
> > +#define _VLV_PCS23_DW11_CH1		0x282c
> > +#define VLV_PCS01_DW11(ch) _PORT(ch, _VLV_PCS01_DW0_CH0, _VLV_PCS01_DW0_CH1)
> > +#define VLV_PCS23_DW11(ch) _PORT(ch, _VLV_PCS23_DW0_CH0, _VLV_PCS23_DW0_CH1)
> > +
> >  #define _VLV_PCS_DW12_CH0		0x8230
> >  #define _VLV_PCS_DW12_CH1		0x8430
> >  #define VLV_PCS_DW12(ch) _PORT(ch, _VLV_PCS_DW12_CH0, _VLV_PCS_DW12_CH1)
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index c59e8fc..814a950 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -2139,6 +2139,29 @@ static void chv_pre_enable_dp(struct intel_encoder *encoder)
> >  
> >  	mutex_lock(&dev_priv->dpio_lock);
> >  
> > +	/* TX FIFO reset source */
> > +	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW0(ch));
> > +	val |= DPIO_LEFT_TXFIFO_RST_MASTER2;
> > +	val &= ~DPIO_LEFT_TXFIFO_RST_MASTER2;
> > +	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW0(ch), val);
> > +
> > +	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW11(ch));
> > +	val &= ~DPIO_LEFT_TXFIFO_RST_MASTER;
> > +	val &= ~DPIO_RIGHT_TXFIFO_RST_MASTER;
> > +	val |= DPIO_LANEDESKEW_STRAP_OVRD;
> > +	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW11(ch), val);
> > +
> > +	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW0(ch));
> > +	val &= ~DPIO_LEFT_TXFIFO_RST_MASTER2;
> > +	val &= ~DPIO_RIGHT_TXFIFO_RST_MASTER2;
> > +	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW0(ch), val);
> > +
> > +	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW11(ch));
> > +	val &= ~DPIO_LEFT_TXFIFO_RST_MASTER;
> > +	val |= DPIO_RIGHT_TXFIFO_RST_MASTER;
> > +	val |= DPIO_LANEDESKEW_STRAP_OVRD;
> > +	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW11(ch), val);
> > +
> >  	/* Deassert soft data lane reset*/
> >  	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW1(ch));
> >  	val |= CHV_PCS_REQ_SOFTRESET_EN;
> > diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> > index cda6506..47430d5 100644
> > --- a/drivers/gpu/drm/i915/intel_hdmi.c
> > +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> > @@ -1358,6 +1358,29 @@ static void chv_hdmi_pre_enable(struct intel_encoder *encoder)
> >  
> >  	mutex_lock(&dev_priv->dpio_lock);
> >  
> > +	/* TX FIFO reset source */
> > +	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW0(ch));
> > +	val |= DPIO_LEFT_TXFIFO_RST_MASTER2;
> > +	val &= ~DPIO_LEFT_TXFIFO_RST_MASTER2;
> > +	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW0(ch), val);
> > +
> > +	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW11(ch));
> > +	val &= ~DPIO_LEFT_TXFIFO_RST_MASTER;
> > +	val &= ~DPIO_RIGHT_TXFIFO_RST_MASTER;
> > +	val |= DPIO_LANEDESKEW_STRAP_OVRD;
> > +	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW11(ch), val);
> > +
> > +	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW0(ch));
> > +	val &= ~DPIO_LEFT_TXFIFO_RST_MASTER2;
> > +	val &= ~DPIO_RIGHT_TXFIFO_RST_MASTER2;
> > +	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW0(ch), val);
> > +
> > +	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW11(ch));
> > +	val &= ~DPIO_LEFT_TXFIFO_RST_MASTER;
> > +	val |= DPIO_RIGHT_TXFIFO_RST_MASTER;
> > +	val |= DPIO_LANEDESKEW_STRAP_OVRD;
> > +	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW11(ch), val);
> > +
> >  	/* Deassert soft data lane reset*/
> >  	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW1(ch));
> >  	val |= CHV_PCS_REQ_SOFTRESET_EN;
> 
> Did this actually make a difference?  Would be nice to get some
> clarification from the phy guys on this and update our docs...

No. The problems I was having were caused by the other problems (pps and
missing DP/HDMI port register writes). So in the next patch I just went
ahead and cleared the reset override bits. So I think we should just squash
these two patches and be happy with the result. I'll post a squashed
patch...

-- 
Ville Syrjälä
Intel OTC