diff mbox

[v2,1/8] drm/dp: Factor out helper to distinguish between branch and sink devices

Message ID 1477326811-30431-2-git-send-email-imre.deak@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Imre Deak Oct. 24, 2016, 4:33 p.m. UTC
This check is open-coded in a few places, so it makes sense to simplify
things by having a helper for it similar to the rest of DPCD feature
helpers.

v2: (Jani)
- Move the helper to drm_dp_helper.h.
- Split out this change to a separate patch.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Imre Deak <imre.deak@intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 11 ++++-------
 include/drm/drm_dp_helper.h     |  6 ++++++
 2 files changed, 10 insertions(+), 7 deletions(-)

Comments

Jani Nikula Oct. 24, 2016, 5:10 p.m. UTC | #1
On Mon, 24 Oct 2016, Imre Deak <imre.deak@intel.com> wrote:
> This check is open-coded in a few places, so it makes sense to simplify
> things by having a helper for it similar to the rest of DPCD feature
> helpers.
>
> v2: (Jani)
> - Move the helper to drm_dp_helper.h.
> - Split out this change to a separate patch.
>
> Cc: Jani Nikula <jani.nikula@intel.com>
> Cc: dri-devel@lists.freedesktop.org
> Signed-off-by: Imre Deak <imre.deak@intel.com>

DP 1.4 has changed the name of "branch" devices, but I think this is
good.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>


> ---
>  drivers/gpu/drm/i915/intel_dp.c | 11 ++++-------
>  include/drm/drm_dp_helper.h     |  6 ++++++
>  2 files changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index f30db8f..3c2293b 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -1459,8 +1459,7 @@ static void intel_dp_print_hw_revision(struct intel_dp *intel_dp)
>  	if ((drm_debug & DRM_UT_KMS) == 0)
>  		return;
>  
> -	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> -	      DP_DWN_STRM_PORT_PRESENT))
> +	if (!drm_dp_is_branch(intel_dp->dpcd))
>  		return;
>  
>  	len = drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_HW_REV, &rev, 1);
> @@ -1478,8 +1477,7 @@ static void intel_dp_print_sw_revision(struct intel_dp *intel_dp)
>  	if ((drm_debug & DRM_UT_KMS) == 0)
>  		return;
>  
> -	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> -	      DP_DWN_STRM_PORT_PRESENT))
> +	if (!drm_dp_is_branch(intel_dp->dpcd))
>  		return;
>  
>  	len = drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_SW_REV, &rev, 2);
> @@ -3615,8 +3613,7 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
>  	if (!is_edp(intel_dp) && !intel_dp->sink_count)
>  		return false;
>  
> -	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> -	      DP_DWN_STRM_PORT_PRESENT))
> +	if (!drm_dp_is_branch(intel_dp->dpcd))
>  		return true; /* native DP sink */
>  
>  	if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
> @@ -4134,7 +4131,7 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
>  		return connector_status_connected;
>  
>  	/* if there's no downstream port, we're done */
> -	if (!(dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT))
> +	if (!drm_dp_is_branch(dpcd))
>  		return connector_status_connected;
>  
>  	/* If we're HPD-aware, SINK_COUNT changes dynamically */
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> index 2a79882..55bbeb0 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -690,6 +690,12 @@ drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
>  		dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED;
>  }
>  
> +static inline bool
> +drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
> +{
> +	return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT;
> +}
> +
>  /*
>   * DisplayPort AUX channel
>   */
Daniel Vetter Oct. 25, 2016, 6:54 a.m. UTC | #2
On Mon, Oct 24, 2016 at 08:10:46PM +0300, Jani Nikula wrote:
> On Mon, 24 Oct 2016, Imre Deak <imre.deak@intel.com> wrote:
> > This check is open-coded in a few places, so it makes sense to simplify
> > things by having a helper for it similar to the rest of DPCD feature
> > helpers.
> >
> > v2: (Jani)
> > - Move the helper to drm_dp_helper.h.
> > - Split out this change to a separate patch.
> >
> > Cc: Jani Nikula <jani.nikula@intel.com>
> > Cc: dri-devel@lists.freedesktop.org
> > Signed-off-by: Imre Deak <imre.deak@intel.com>
> 
> DP 1.4 has changed the name of "branch" devices, but I think this is
> good.
> 
> Reviewed-by: Jani Nikula <jani.nikula@intel.com>

Applied to drm-misc, thanks.
-Daniel
> 
> 
> > ---
> >  drivers/gpu/drm/i915/intel_dp.c | 11 ++++-------
> >  include/drm/drm_dp_helper.h     |  6 ++++++
> >  2 files changed, 10 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index f30db8f..3c2293b 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -1459,8 +1459,7 @@ static void intel_dp_print_hw_revision(struct intel_dp *intel_dp)
> >  	if ((drm_debug & DRM_UT_KMS) == 0)
> >  		return;
> >  
> > -	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> > -	      DP_DWN_STRM_PORT_PRESENT))
> > +	if (!drm_dp_is_branch(intel_dp->dpcd))
> >  		return;
> >  
> >  	len = drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_HW_REV, &rev, 1);
> > @@ -1478,8 +1477,7 @@ static void intel_dp_print_sw_revision(struct intel_dp *intel_dp)
> >  	if ((drm_debug & DRM_UT_KMS) == 0)
> >  		return;
> >  
> > -	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> > -	      DP_DWN_STRM_PORT_PRESENT))
> > +	if (!drm_dp_is_branch(intel_dp->dpcd))
> >  		return;
> >  
> >  	len = drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_SW_REV, &rev, 2);
> > @@ -3615,8 +3613,7 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> >  	if (!is_edp(intel_dp) && !intel_dp->sink_count)
> >  		return false;
> >  
> > -	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> > -	      DP_DWN_STRM_PORT_PRESENT))
> > +	if (!drm_dp_is_branch(intel_dp->dpcd))
> >  		return true; /* native DP sink */
> >  
> >  	if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
> > @@ -4134,7 +4131,7 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
> >  		return connector_status_connected;
> >  
> >  	/* if there's no downstream port, we're done */
> > -	if (!(dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT))
> > +	if (!drm_dp_is_branch(dpcd))
> >  		return connector_status_connected;
> >  
> >  	/* If we're HPD-aware, SINK_COUNT changes dynamically */
> > diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> > index 2a79882..55bbeb0 100644
> > --- a/include/drm/drm_dp_helper.h
> > +++ b/include/drm/drm_dp_helper.h
> > @@ -690,6 +690,12 @@ drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
> >  		dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED;
> >  }
> >  
> > +static inline bool
> > +drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
> > +{
> > +	return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT;
> > +}
> > +
> >  /*
> >   * DisplayPort AUX channel
> >   */
> 
> -- 
> Jani Nikula, Intel Open Source Technology Center
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Jani Nikula Oct. 25, 2016, 7:46 a.m. UTC | #3
On Tue, 25 Oct 2016, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Mon, Oct 24, 2016 at 08:10:46PM +0300, Jani Nikula wrote:
>> On Mon, 24 Oct 2016, Imre Deak <imre.deak@intel.com> wrote:
>> > This check is open-coded in a few places, so it makes sense to simplify
>> > things by having a helper for it similar to the rest of DPCD feature
>> > helpers.
>> >
>> > v2: (Jani)
>> > - Move the helper to drm_dp_helper.h.
>> > - Split out this change to a separate patch.
>> >
>> > Cc: Jani Nikula <jani.nikula@intel.com>
>> > Cc: dri-devel@lists.freedesktop.org
>> > Signed-off-by: Imre Deak <imre.deak@intel.com>
>> 
>> DP 1.4 has changed the name of "branch" devices, but I think this is
>> good.
>> 
>> Reviewed-by: Jani Nikula <jani.nikula@intel.com>
>
> Applied to drm-misc, thanks.

Thanks, but... that actually makes this series harder to land. We can't
move forward with the i915 changes before a backmerge to dinq with this
helper included.

BR,
Jani.

> -Daniel
>> 
>> 
>> > ---
>> >  drivers/gpu/drm/i915/intel_dp.c | 11 ++++-------
>> >  include/drm/drm_dp_helper.h     |  6 ++++++
>> >  2 files changed, 10 insertions(+), 7 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>> > index f30db8f..3c2293b 100644
>> > --- a/drivers/gpu/drm/i915/intel_dp.c
>> > +++ b/drivers/gpu/drm/i915/intel_dp.c
>> > @@ -1459,8 +1459,7 @@ static void intel_dp_print_hw_revision(struct intel_dp *intel_dp)
>> >  	if ((drm_debug & DRM_UT_KMS) == 0)
>> >  		return;
>> >  
>> > -	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
>> > -	      DP_DWN_STRM_PORT_PRESENT))
>> > +	if (!drm_dp_is_branch(intel_dp->dpcd))
>> >  		return;
>> >  
>> >  	len = drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_HW_REV, &rev, 1);
>> > @@ -1478,8 +1477,7 @@ static void intel_dp_print_sw_revision(struct intel_dp *intel_dp)
>> >  	if ((drm_debug & DRM_UT_KMS) == 0)
>> >  		return;
>> >  
>> > -	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
>> > -	      DP_DWN_STRM_PORT_PRESENT))
>> > +	if (!drm_dp_is_branch(intel_dp->dpcd))
>> >  		return;
>> >  
>> >  	len = drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_SW_REV, &rev, 2);
>> > @@ -3615,8 +3613,7 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
>> >  	if (!is_edp(intel_dp) && !intel_dp->sink_count)
>> >  		return false;
>> >  
>> > -	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
>> > -	      DP_DWN_STRM_PORT_PRESENT))
>> > +	if (!drm_dp_is_branch(intel_dp->dpcd))
>> >  		return true; /* native DP sink */
>> >  
>> >  	if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
>> > @@ -4134,7 +4131,7 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
>> >  		return connector_status_connected;
>> >  
>> >  	/* if there's no downstream port, we're done */
>> > -	if (!(dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT))
>> > +	if (!drm_dp_is_branch(dpcd))
>> >  		return connector_status_connected;
>> >  
>> >  	/* If we're HPD-aware, SINK_COUNT changes dynamically */
>> > diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
>> > index 2a79882..55bbeb0 100644
>> > --- a/include/drm/drm_dp_helper.h
>> > +++ b/include/drm/drm_dp_helper.h
>> > @@ -690,6 +690,12 @@ drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
>> >  		dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED;
>> >  }
>> >  
>> > +static inline bool
>> > +drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
>> > +{
>> > +	return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT;
>> > +}
>> > +
>> >  /*
>> >   * DisplayPort AUX channel
>> >   */
>> 
>> -- 
>> Jani Nikula, Intel Open Source Technology Center
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Daniel Vetter Oct. 25, 2016, 8:12 a.m. UTC | #4
On Tue, Oct 25, 2016 at 10:46:44AM +0300, Jani Nikula wrote:
> On Tue, 25 Oct 2016, Daniel Vetter <daniel@ffwll.ch> wrote:
> > On Mon, Oct 24, 2016 at 08:10:46PM +0300, Jani Nikula wrote:
> >> On Mon, 24 Oct 2016, Imre Deak <imre.deak@intel.com> wrote:
> >> > This check is open-coded in a few places, so it makes sense to simplify
> >> > things by having a helper for it similar to the rest of DPCD feature
> >> > helpers.
> >> >
> >> > v2: (Jani)
> >> > - Move the helper to drm_dp_helper.h.
> >> > - Split out this change to a separate patch.
> >> >
> >> > Cc: Jani Nikula <jani.nikula@intel.com>
> >> > Cc: dri-devel@lists.freedesktop.org
> >> > Signed-off-by: Imre Deak <imre.deak@intel.com>
> >> 
> >> DP 1.4 has changed the name of "branch" devices, but I think this is
> >> good.
> >> 
> >> Reviewed-by: Jani Nikula <jani.nikula@intel.com>
> >
> > Applied to drm-misc, thanks.
> 
> Thanks, but... that actually makes this series harder to land. We can't
> move forward with the i915 changes before a backmerge to dinq with this
> helper included.

Oh garbage, I thought it was 1/1. Should wait for coffee to kick in first.
I guess just apply it to drm-intel also, and we'll deal with the fallout
(I can't rebase and all that).
-Daniel

> 
> BR,
> Jani.
> 
> > -Daniel
> >> 
> >> 
> >> > ---
> >> >  drivers/gpu/drm/i915/intel_dp.c | 11 ++++-------
> >> >  include/drm/drm_dp_helper.h     |  6 ++++++
> >> >  2 files changed, 10 insertions(+), 7 deletions(-)
> >> >
> >> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> >> > index f30db8f..3c2293b 100644
> >> > --- a/drivers/gpu/drm/i915/intel_dp.c
> >> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> >> > @@ -1459,8 +1459,7 @@ static void intel_dp_print_hw_revision(struct intel_dp *intel_dp)
> >> >  	if ((drm_debug & DRM_UT_KMS) == 0)
> >> >  		return;
> >> >  
> >> > -	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> >> > -	      DP_DWN_STRM_PORT_PRESENT))
> >> > +	if (!drm_dp_is_branch(intel_dp->dpcd))
> >> >  		return;
> >> >  
> >> >  	len = drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_HW_REV, &rev, 1);
> >> > @@ -1478,8 +1477,7 @@ static void intel_dp_print_sw_revision(struct intel_dp *intel_dp)
> >> >  	if ((drm_debug & DRM_UT_KMS) == 0)
> >> >  		return;
> >> >  
> >> > -	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> >> > -	      DP_DWN_STRM_PORT_PRESENT))
> >> > +	if (!drm_dp_is_branch(intel_dp->dpcd))
> >> >  		return;
> >> >  
> >> >  	len = drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_SW_REV, &rev, 2);
> >> > @@ -3615,8 +3613,7 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> >> >  	if (!is_edp(intel_dp) && !intel_dp->sink_count)
> >> >  		return false;
> >> >  
> >> > -	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> >> > -	      DP_DWN_STRM_PORT_PRESENT))
> >> > +	if (!drm_dp_is_branch(intel_dp->dpcd))
> >> >  		return true; /* native DP sink */
> >> >  
> >> >  	if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
> >> > @@ -4134,7 +4131,7 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
> >> >  		return connector_status_connected;
> >> >  
> >> >  	/* if there's no downstream port, we're done */
> >> > -	if (!(dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT))
> >> > +	if (!drm_dp_is_branch(dpcd))
> >> >  		return connector_status_connected;
> >> >  
> >> >  	/* If we're HPD-aware, SINK_COUNT changes dynamically */
> >> > diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> >> > index 2a79882..55bbeb0 100644
> >> > --- a/include/drm/drm_dp_helper.h
> >> > +++ b/include/drm/drm_dp_helper.h
> >> > @@ -690,6 +690,12 @@ drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
> >> >  		dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED;
> >> >  }
> >> >  
> >> > +static inline bool
> >> > +drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
> >> > +{
> >> > +	return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT;
> >> > +}
> >> > +
> >> >  /*
> >> >   * DisplayPort AUX channel
> >> >   */
> >> 
> >> -- 
> >> Jani Nikula, Intel Open Source Technology Center
> >> _______________________________________________
> >> Intel-gfx mailing list
> >> Intel-gfx@lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Jani Nikula, Intel Open Source Technology Center
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index f30db8f..3c2293b 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1459,8 +1459,7 @@  static void intel_dp_print_hw_revision(struct intel_dp *intel_dp)
 	if ((drm_debug & DRM_UT_KMS) == 0)
 		return;
 
-	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
-	      DP_DWN_STRM_PORT_PRESENT))
+	if (!drm_dp_is_branch(intel_dp->dpcd))
 		return;
 
 	len = drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_HW_REV, &rev, 1);
@@ -1478,8 +1477,7 @@  static void intel_dp_print_sw_revision(struct intel_dp *intel_dp)
 	if ((drm_debug & DRM_UT_KMS) == 0)
 		return;
 
-	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
-	      DP_DWN_STRM_PORT_PRESENT))
+	if (!drm_dp_is_branch(intel_dp->dpcd))
 		return;
 
 	len = drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_SW_REV, &rev, 2);
@@ -3615,8 +3613,7 @@  intel_dp_get_dpcd(struct intel_dp *intel_dp)
 	if (!is_edp(intel_dp) && !intel_dp->sink_count)
 		return false;
 
-	if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
-	      DP_DWN_STRM_PORT_PRESENT))
+	if (!drm_dp_is_branch(intel_dp->dpcd))
 		return true; /* native DP sink */
 
 	if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
@@ -4134,7 +4131,7 @@  intel_dp_detect_dpcd(struct intel_dp *intel_dp)
 		return connector_status_connected;
 
 	/* if there's no downstream port, we're done */
-	if (!(dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT))
+	if (!drm_dp_is_branch(dpcd))
 		return connector_status_connected;
 
 	/* If we're HPD-aware, SINK_COUNT changes dynamically */
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 2a79882..55bbeb0 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -690,6 +690,12 @@  drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 		dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED;
 }
 
+static inline bool
+drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT;
+}
+
 /*
  * DisplayPort AUX channel
  */