[v3,2/2] drm/i915/dp: Helper to check for DDI BUF status to get active
diff mbox series

Message ID 20200624221108.10038-2-manasi.d.navare@intel.com
State New
Headers show
Series
  • [v3,1/2] drm/i915/dp: Helper for checking DDI_BUF_CTL Idle status
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Commit Message

Manasi Navare June 24, 2020, 10:11 p.m. UTC
Based on the platform, Bspec expects us to wait or poll with
timeout for DDI BUF IDLE bit to be set to 0 (non idle) or get active
after enabling DDI_BUF_CTL.

v3:
* Add a new function _active for DDI BUF CTL to be non idle (Ville)
v2:
* Based on platform, fixed delay or poll (Ville)
* Use a helper to do this (Imre, Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

Comments

Ville Syrjälä June 25, 2020, 9:28 p.m. UTC | #1
On Wed, Jun 24, 2020 at 03:11:08PM -0700, Manasi Navare wrote:
> Based on the platform, Bspec expects us to wait or poll with
> timeout for DDI BUF IDLE bit to be set to 0 (non idle) or get active
> after enabling DDI_BUF_CTL.
> 
> v3:
> * Add a new function _active for DDI BUF CTL to be non idle (Ville)
> v2:
> * Based on platform, fixed delay or poll (Ville)
> * Use a helper to do this (Imre, Ville)
> 
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Imre Deak <imre.deak@intel.com>
> Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 7d5c8ab88fc4..ff6b1e9d1b4e 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -1195,6 +1195,20 @@ static void intel_wait_ddi_buf_idle(struct drm_i915_private *dev_priv,
>  			port_name(port));
>  }
>  
> +static void intel_wait_ddi_buf_active(struct drm_i915_private *dev_priv,
> +				      enum port port)
> +{
> +	if (INTEL_GEN(dev_priv) <= 9) {

Didn't we want the poll approach for glk+?

> +		usleep_range(600, 1000);
> +		return;
> +	}
> +
> +	if (wait_for_us(!(intel_de_read(dev_priv, DDI_BUF_CTL(port)) &
> +			  DDI_BUF_IS_IDLE), 600))
> +		drm_err(&dev_priv->drm, "Timeout waiting for DDI BUF %c to get active\n",
> +			port_name(port));
> +}
> +
>  static u32 hsw_pll_to_ddi_pll_sel(const struct intel_shared_dpll *pll)
>  {
>  	switch (pll->info->id) {
> @@ -4020,7 +4034,7 @@ static void intel_ddi_prepare_link_retrain(struct intel_dp *intel_dp)
>  	intel_de_write(dev_priv, DDI_BUF_CTL(port), intel_dp->DP);
>  	intel_de_posting_read(dev_priv, DDI_BUF_CTL(port));
>  
> -	udelay(600);
> +	intel_wait_ddi_buf_active(dev_priv, port);

Missed the FDI case.

Also we're still missing this for HDMI, on icl+ I think? Can't quite
remember if that was where the spec started to demand it.

>  }
>  
>  static void intel_ddi_set_link_train(struct intel_dp *intel_dp,
> -- 
> 2.19.1
Manasi Navare June 25, 2020, 9:59 p.m. UTC | #2
On Fri, Jun 26, 2020 at 12:28:53AM +0300, Ville Syrjälä wrote:
> On Wed, Jun 24, 2020 at 03:11:08PM -0700, Manasi Navare wrote:
> > Based on the platform, Bspec expects us to wait or poll with
> > timeout for DDI BUF IDLE bit to be set to 0 (non idle) or get active
> > after enabling DDI_BUF_CTL.
> > 
> > v3:
> > * Add a new function _active for DDI BUF CTL to be non idle (Ville)
> > v2:
> > * Based on platform, fixed delay or poll (Ville)
> > * Use a helper to do this (Imre, Ville)
> > 
> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > Cc: Imre Deak <imre.deak@intel.com>
> > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_ddi.c | 16 +++++++++++++++-
> >  1 file changed, 15 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> > index 7d5c8ab88fc4..ff6b1e9d1b4e 100644
> > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > @@ -1195,6 +1195,20 @@ static void intel_wait_ddi_buf_idle(struct drm_i915_private *dev_priv,
> >  			port_name(port));
> >  }
> >  
> > +static void intel_wait_ddi_buf_active(struct drm_i915_private *dev_priv,
> > +				      enum port port)
> > +{
> > +	if (INTEL_GEN(dev_priv) <= 9) {
> 
> Didn't we want the poll approach for glk+?

But other Gen9s like SKL is still a fixed delay so may be add a GEN <=9 & !GLK here would do?

Manasi

> 
> > +		usleep_range(600, 1000);
> > +		return;
> > +	}
> > +
> > +	if (wait_for_us(!(intel_de_read(dev_priv, DDI_BUF_CTL(port)) &
> > +			  DDI_BUF_IS_IDLE), 600))
> > +		drm_err(&dev_priv->drm, "Timeout waiting for DDI BUF %c to get active\n",
> > +			port_name(port));
> > +}
> > +
> >  static u32 hsw_pll_to_ddi_pll_sel(const struct intel_shared_dpll *pll)
> >  {
> >  	switch (pll->info->id) {
> > @@ -4020,7 +4034,7 @@ static void intel_ddi_prepare_link_retrain(struct intel_dp *intel_dp)
> >  	intel_de_write(dev_priv, DDI_BUF_CTL(port), intel_dp->DP);
> >  	intel_de_posting_read(dev_priv, DDI_BUF_CTL(port));
> >  
> > -	udelay(600);
> > +	intel_wait_ddi_buf_active(dev_priv, port);
> 
> Missed the FDI case.
> 
> Also we're still missing this for HDMI, on icl+ I think? Can't quite
> remember if that was where the spec started to demand it.
> 
> >  }
> >  
> >  static void intel_ddi_set_link_train(struct intel_dp *intel_dp,
> > -- 
> > 2.19.1
> 
> -- 
> Ville Syrjälä
> Intel
Manasi Navare June 25, 2020, 10:04 p.m. UTC | #3
On Fri, Jun 26, 2020 at 12:28:53AM +0300, Ville Syrjälä wrote:
> On Wed, Jun 24, 2020 at 03:11:08PM -0700, Manasi Navare wrote:
> > Based on the platform, Bspec expects us to wait or poll with
> > timeout for DDI BUF IDLE bit to be set to 0 (non idle) or get active
> > after enabling DDI_BUF_CTL.
> > 
> > v3:
> > * Add a new function _active for DDI BUF CTL to be non idle (Ville)
> > v2:
> > * Based on platform, fixed delay or poll (Ville)
> > * Use a helper to do this (Imre, Ville)
> > 
> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > Cc: Imre Deak <imre.deak@intel.com>
> > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_ddi.c | 16 +++++++++++++++-
> >  1 file changed, 15 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> > index 7d5c8ab88fc4..ff6b1e9d1b4e 100644
> > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > @@ -1195,6 +1195,20 @@ static void intel_wait_ddi_buf_idle(struct drm_i915_private *dev_priv,
> >  			port_name(port));
> >  }
> >  
> > +static void intel_wait_ddi_buf_active(struct drm_i915_private *dev_priv,
> > +				      enum port port)
> > +{
> > +	if (INTEL_GEN(dev_priv) <= 9) {
> 
> Didn't we want the poll approach for glk+?

Actually in the bspec I only see Gen10+ has a 500usecs timeout

Manasi
> 
> > +		usleep_range(600, 1000);
> > +		return;
> > +	}
> > +
> > +	if (wait_for_us(!(intel_de_read(dev_priv, DDI_BUF_CTL(port)) &
> > +			  DDI_BUF_IS_IDLE), 600))
> > +		drm_err(&dev_priv->drm, "Timeout waiting for DDI BUF %c to get active\n",
> > +			port_name(port));
> > +}
> > +
> >  static u32 hsw_pll_to_ddi_pll_sel(const struct intel_shared_dpll *pll)
> >  {
> >  	switch (pll->info->id) {
> > @@ -4020,7 +4034,7 @@ static void intel_ddi_prepare_link_retrain(struct intel_dp *intel_dp)
> >  	intel_de_write(dev_priv, DDI_BUF_CTL(port), intel_dp->DP);
> >  	intel_de_posting_read(dev_priv, DDI_BUF_CTL(port));
> >  
> > -	udelay(600);
> > +	intel_wait_ddi_buf_active(dev_priv, port);
> 
> Missed the FDI case.
> 
> Also we're still missing this for HDMI, on icl+ I think? Can't quite
> remember if that was where the spec started to demand it.
> 
> >  }
> >  
> >  static void intel_ddi_set_link_train(struct intel_dp *intel_dp,
> > -- 
> > 2.19.1
> 
> -- 
> Ville Syrjälä
> Intel
Ville Syrjälä June 25, 2020, 10:16 p.m. UTC | #4
On Thu, Jun 25, 2020 at 03:04:33PM -0700, Manasi Navare wrote:
> On Fri, Jun 26, 2020 at 12:28:53AM +0300, Ville Syrjälä wrote:
> > On Wed, Jun 24, 2020 at 03:11:08PM -0700, Manasi Navare wrote:
> > > Based on the platform, Bspec expects us to wait or poll with
> > > timeout for DDI BUF IDLE bit to be set to 0 (non idle) or get active
> > > after enabling DDI_BUF_CTL.
> > > 
> > > v3:
> > > * Add a new function _active for DDI BUF CTL to be non idle (Ville)
> > > v2:
> > > * Based on platform, fixed delay or poll (Ville)
> > > * Use a helper to do this (Imre, Ville)
> > > 
> > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > Cc: Imre Deak <imre.deak@intel.com>
> > > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/display/intel_ddi.c | 16 +++++++++++++++-
> > >  1 file changed, 15 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > index 7d5c8ab88fc4..ff6b1e9d1b4e 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > @@ -1195,6 +1195,20 @@ static void intel_wait_ddi_buf_idle(struct drm_i915_private *dev_priv,
> > >  			port_name(port));
> > >  }
> > >  
> > > +static void intel_wait_ddi_buf_active(struct drm_i915_private *dev_priv,
> > > +				      enum port port)
> > > +{
> > > +	if (INTEL_GEN(dev_priv) <= 9) {
> > 
> > Didn't we want the poll approach for glk+?
> 
> Actually in the bspec I only see Gen10+ has a 500usecs timeout

glk has (mostly) gen10 display.

Defacto standard form to write that test is
'GEN < 10 && !IS_GLK'.

> 
> Manasi
> > 
> > > +		usleep_range(600, 1000);
> > > +		return;
> > > +	}
> > > +
> > > +	if (wait_for_us(!(intel_de_read(dev_priv, DDI_BUF_CTL(port)) &
> > > +			  DDI_BUF_IS_IDLE), 600))
> > > +		drm_err(&dev_priv->drm, "Timeout waiting for DDI BUF %c to get active\n",
> > > +			port_name(port));
> > > +}
> > > +
> > >  static u32 hsw_pll_to_ddi_pll_sel(const struct intel_shared_dpll *pll)
> > >  {
> > >  	switch (pll->info->id) {
> > > @@ -4020,7 +4034,7 @@ static void intel_ddi_prepare_link_retrain(struct intel_dp *intel_dp)
> > >  	intel_de_write(dev_priv, DDI_BUF_CTL(port), intel_dp->DP);
> > >  	intel_de_posting_read(dev_priv, DDI_BUF_CTL(port));
> > >  
> > > -	udelay(600);
> > > +	intel_wait_ddi_buf_active(dev_priv, port);
> > 
> > Missed the FDI case.
> > 
> > Also we're still missing this for HDMI, on icl+ I think? Can't quite
> > remember if that was where the spec started to demand it.
> > 
> > >  }
> > >  
> > >  static void intel_ddi_set_link_train(struct intel_dp *intel_dp,
> > > -- 
> > > 2.19.1
> > 
> > -- 
> > Ville Syrjälä
> > Intel
Manasi Navare June 25, 2020, 10:27 p.m. UTC | #5
On Fri, Jun 26, 2020 at 01:16:42AM +0300, Ville Syrjälä wrote:
> On Thu, Jun 25, 2020 at 03:04:33PM -0700, Manasi Navare wrote:
> > On Fri, Jun 26, 2020 at 12:28:53AM +0300, Ville Syrjälä wrote:
> > > On Wed, Jun 24, 2020 at 03:11:08PM -0700, Manasi Navare wrote:
> > > > Based on the platform, Bspec expects us to wait or poll with
> > > > timeout for DDI BUF IDLE bit to be set to 0 (non idle) or get active
> > > > after enabling DDI_BUF_CTL.
> > > > 
> > > > v3:
> > > > * Add a new function _active for DDI BUF CTL to be non idle (Ville)
> > > > v2:
> > > > * Based on platform, fixed delay or poll (Ville)
> > > > * Use a helper to do this (Imre, Ville)
> > > > 
> > > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > > Cc: Imre Deak <imre.deak@intel.com>
> > > > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> > > > ---
> > > >  drivers/gpu/drm/i915/display/intel_ddi.c | 16 +++++++++++++++-
> > > >  1 file changed, 15 insertions(+), 1 deletion(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > > index 7d5c8ab88fc4..ff6b1e9d1b4e 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > > @@ -1195,6 +1195,20 @@ static void intel_wait_ddi_buf_idle(struct drm_i915_private *dev_priv,
> > > >  			port_name(port));
> > > >  }
> > > >  
> > > > +static void intel_wait_ddi_buf_active(struct drm_i915_private *dev_priv,
> > > > +				      enum port port)
> > > > +{
> > > > +	if (INTEL_GEN(dev_priv) <= 9) {
> > > 
> > > Didn't we want the poll approach for glk+?
> > 
> > Actually in the bspec I only see Gen10+ has a 500usecs timeout
> 
> glk has (mostly) gen10 display.
> 
> Defacto standard form to write that test is
> 'GEN < 10 && !IS_GLK'.

Okay will update this and send in the next rev

Manasi

> 
> > 
> > Manasi
> > > 
> > > > +		usleep_range(600, 1000);
> > > > +		return;
> > > > +	}
> > > > +
> > > > +	if (wait_for_us(!(intel_de_read(dev_priv, DDI_BUF_CTL(port)) &
> > > > +			  DDI_BUF_IS_IDLE), 600))
> > > > +		drm_err(&dev_priv->drm, "Timeout waiting for DDI BUF %c to get active\n",
> > > > +			port_name(port));
> > > > +}
> > > > +
> > > >  static u32 hsw_pll_to_ddi_pll_sel(const struct intel_shared_dpll *pll)
> > > >  {
> > > >  	switch (pll->info->id) {
> > > > @@ -4020,7 +4034,7 @@ static void intel_ddi_prepare_link_retrain(struct intel_dp *intel_dp)
> > > >  	intel_de_write(dev_priv, DDI_BUF_CTL(port), intel_dp->DP);
> > > >  	intel_de_posting_read(dev_priv, DDI_BUF_CTL(port));
> > > >  
> > > > -	udelay(600);
> > > > +	intel_wait_ddi_buf_active(dev_priv, port);
> > > 
> > > Missed the FDI case.
> > > 
> > > Also we're still missing this for HDMI, on icl+ I think? Can't quite
> > > remember if that was where the spec started to demand it.
> > > 
> > > >  }
> > > >  
> > > >  static void intel_ddi_set_link_train(struct intel_dp *intel_dp,
> > > > -- 
> > > > 2.19.1
> > > 
> > > -- 
> > > Ville Syrjälä
> > > Intel
> 
> -- 
> Ville Syrjälä
> Intel

Patch
diff mbox series

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 7d5c8ab88fc4..ff6b1e9d1b4e 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -1195,6 +1195,20 @@  static void intel_wait_ddi_buf_idle(struct drm_i915_private *dev_priv,
 			port_name(port));
 }
 
+static void intel_wait_ddi_buf_active(struct drm_i915_private *dev_priv,
+				      enum port port)
+{
+	if (INTEL_GEN(dev_priv) <= 9) {
+		usleep_range(600, 1000);
+		return;
+	}
+
+	if (wait_for_us(!(intel_de_read(dev_priv, DDI_BUF_CTL(port)) &
+			  DDI_BUF_IS_IDLE), 600))
+		drm_err(&dev_priv->drm, "Timeout waiting for DDI BUF %c to get active\n",
+			port_name(port));
+}
+
 static u32 hsw_pll_to_ddi_pll_sel(const struct intel_shared_dpll *pll)
 {
 	switch (pll->info->id) {
@@ -4020,7 +4034,7 @@  static void intel_ddi_prepare_link_retrain(struct intel_dp *intel_dp)
 	intel_de_write(dev_priv, DDI_BUF_CTL(port), intel_dp->DP);
 	intel_de_posting_read(dev_priv, DDI_BUF_CTL(port));
 
-	udelay(600);
+	intel_wait_ddi_buf_active(dev_priv, port);
 }
 
 static void intel_ddi_set_link_train(struct intel_dp *intel_dp,