[v7,3/5] drm: Document variable refresh properties

Submitted by Kazlauskas, Nicholas on Nov. 8, 2018, 2:43 p.m.

Details

Message ID 20181108144353.31363-4-nicholas.kazlauskas@amd.com
State New
Headers show
Series "A DRM API for adaptive sync and variable refresh rate support" ( rev: 7 ) in AMD X.Org drivers

Not browsing as part of any series.

Commit Message

Kazlauskas, Nicholas Nov. 8, 2018, 2:43 p.m.
These include the drm_connector 'vrr_capable' and the drm_crtc
'vrr_enabled' properties.

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Pekka Paalanen <ppaalanen@gmail.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Michel Dänzer <michel@daenzer.net>
---
 Documentation/gpu/drm-kms.rst   |  7 ++++
 drivers/gpu/drm/drm_connector.c | 68 +++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+)

Patch hide | download patch | download mbox

diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
index 4b1501b4835b..8da2a178cf85 100644
--- a/Documentation/gpu/drm-kms.rst
+++ b/Documentation/gpu/drm-kms.rst
@@ -575,6 +575,13 @@  Explicit Fencing Properties
 .. kernel-doc:: drivers/gpu/drm/drm_atomic_uapi.c
    :doc: explicit fencing properties
 
+
+Variable Refresh Properties
+---------------------------
+
+.. kernel-doc:: drivers/gpu/drm/drm_connector.c
+   :doc: Variable refresh properties
+
 Existing KMS Properties
 -----------------------
 
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 49290060ab7b..0e4287461997 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -1255,6 +1255,74 @@  int drm_mode_create_scaling_mode_property(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_mode_create_scaling_mode_property);
 
+/**
+ * DOC: Variable refresh properties
+ *
+ * Variable refresh rate capable displays can dynamically adjust their
+ * refresh rate by extending the duration of their vertical front porch
+ * until page flip or timeout occurs. This can reduce or remove stuttering
+ * and latency in scenarios where the page flip does not align with the
+ * vblank interval.
+ *
+ * An example scenario would be an application flipping at a constant rate
+ * of 48Hz on a 60Hz display. The page flip will frequently miss the vblank
+ * interval and the same contents will be displayed twice. This can be
+ * observed as stuttering for content with motion.
+ *
+ * If variable refresh rate was active on a display that supported a
+ * variable refresh range from 35Hz to 60Hz no stuttering would be observable
+ * for the example scenario. The minimum supported variable refresh rate of
+ * 35Hz is below the page flip frequency and the vertical front porch can
+ * be extended until the page flip occurs. The vblank interval will be
+ * directly aligned to the page flip rate.
+ *
+ * Not all userspace content is suitable for use with variable refresh rate.
+ * Large and frequent changes in vertical front porch duration may worsen
+ * perceived stuttering for input sensitive applications.
+ *
+ * Panel brightness will also vary with vertical front porch duration. Some
+ * panels may have noticeable differences in brightness between the minimum
+ * vertical front porch duration and the maximum vertical front porch duration.
+ * Large and frequent changes in vertical front porch duration may produce
+ * observable flickering for such panels.
+ *
+ * Userspace control for variable refresh rate is supported via properties
+ * on the &drm_connector and &drm_crtc objects.
+ *
+ * "vrr_capable":
+ *	Optional &drm_connector boolean property that drivers should attach
+ *	with drm_connector_attach_vrr_capable_property() on connectors that
+ *	could support variable refresh rates. Drivers should update the
+ *	property value by calling drm_connector_set_vrr_capable_property().
+ *
+ *	Absence of the property should indicate absence of support.
+ *
+ * "vrr_enabled":
+ *	Default &drm_crtc boolean property that notifies the driver that the
+ *	content on the CRTC is suitable for variable refresh rate presentation.
+ *	The driver will take this property as a hint to enable variable
+ *	refresh rate support if the receiver supports it, ie. if the
+ *	"vrr_capable" property is true on the &drm_connector object. The
+ *	vertical front porch duration will be extended until page-flip or
+ *	timeout when enabled.
+ *
+ *	The minimum vertical front porch duration is defined as the vertical
+ *	front porch duration for the current mode.
+ *
+ *	The maximum vertical front porch duration is greater than or equal to
+ *	the minimum vertical front porch duration. The duration is derived
+ *	from the minimum supported variable refresh rate for the connector.
+ *
+ *	The driver may place further restrictions within these minimum
+ *	and maximum bounds.
+ *
+ *	The semantics for the vertical blank timestamp differ when
+ *	variable refresh rate is active. The vertical blank timestamp
+ *	is defined to be an estimate using the current mode's fixed
+ *	refresh rate timings. The semantics for the page-flip event
+ *	timestamp remain the same.
+ */
+
 /**
  * drm_connector_attach_vrr_capable_property - creates the
  * vrr_capable property

Comments

On 2018-11-08 9:43 a.m., Nicholas Kazlauskas wrote:
> These include the drm_connector 'vrr_capable' and the drm_crtc

> 'vrr_enabled' properties.

> 

> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>

> Cc: Harry Wentland <harry.wentland@amd.com>

> Cc: Manasi Navare <manasi.d.navare@intel.com>

> Cc: Pekka Paalanen <ppaalanen@gmail.com>

> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>

> Cc: Michel Dänzer <michel@daenzer.net>


Looks good. Whole series is
Reviewed-by: Harry Wentland <harry.wentland@amd.com>


How are we with the userspace patches? We should probably hold off pushing the kernel patches until the userspace work is all reviewed.

Harry

> ---

>  Documentation/gpu/drm-kms.rst   |  7 ++++

>  drivers/gpu/drm/drm_connector.c | 68 +++++++++++++++++++++++++++++++++

>  2 files changed, 75 insertions(+)

> 

> diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst

> index 4b1501b4835b..8da2a178cf85 100644

> --- a/Documentation/gpu/drm-kms.rst

> +++ b/Documentation/gpu/drm-kms.rst

> @@ -575,6 +575,13 @@ Explicit Fencing Properties

>  .. kernel-doc:: drivers/gpu/drm/drm_atomic_uapi.c

>     :doc: explicit fencing properties

>  

> +

> +Variable Refresh Properties

> +---------------------------

> +

> +.. kernel-doc:: drivers/gpu/drm/drm_connector.c

> +   :doc: Variable refresh properties

> +

>  Existing KMS Properties

>  -----------------------

>  

> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c

> index 49290060ab7b..0e4287461997 100644

> --- a/drivers/gpu/drm/drm_connector.c

> +++ b/drivers/gpu/drm/drm_connector.c

> @@ -1255,6 +1255,74 @@ int drm_mode_create_scaling_mode_property(struct drm_device *dev)

>  }

>  EXPORT_SYMBOL(drm_mode_create_scaling_mode_property);

>  

> +/**

> + * DOC: Variable refresh properties

> + *

> + * Variable refresh rate capable displays can dynamically adjust their

> + * refresh rate by extending the duration of their vertical front porch

> + * until page flip or timeout occurs. This can reduce or remove stuttering

> + * and latency in scenarios where the page flip does not align with the

> + * vblank interval.

> + *

> + * An example scenario would be an application flipping at a constant rate

> + * of 48Hz on a 60Hz display. The page flip will frequently miss the vblank

> + * interval and the same contents will be displayed twice. This can be

> + * observed as stuttering for content with motion.

> + *

> + * If variable refresh rate was active on a display that supported a

> + * variable refresh range from 35Hz to 60Hz no stuttering would be observable

> + * for the example scenario. The minimum supported variable refresh rate of

> + * 35Hz is below the page flip frequency and the vertical front porch can

> + * be extended until the page flip occurs. The vblank interval will be

> + * directly aligned to the page flip rate.

> + *

> + * Not all userspace content is suitable for use with variable refresh rate.

> + * Large and frequent changes in vertical front porch duration may worsen

> + * perceived stuttering for input sensitive applications.

> + *

> + * Panel brightness will also vary with vertical front porch duration. Some

> + * panels may have noticeable differences in brightness between the minimum

> + * vertical front porch duration and the maximum vertical front porch duration.

> + * Large and frequent changes in vertical front porch duration may produce

> + * observable flickering for such panels.

> + *

> + * Userspace control for variable refresh rate is supported via properties

> + * on the &drm_connector and &drm_crtc objects.

> + *

> + * "vrr_capable":

> + *	Optional &drm_connector boolean property that drivers should attach

> + *	with drm_connector_attach_vrr_capable_property() on connectors that

> + *	could support variable refresh rates. Drivers should update the

> + *	property value by calling drm_connector_set_vrr_capable_property().

> + *

> + *	Absence of the property should indicate absence of support.

> + *

> + * "vrr_enabled":

> + *	Default &drm_crtc boolean property that notifies the driver that the

> + *	content on the CRTC is suitable for variable refresh rate presentation.

> + *	The driver will take this property as a hint to enable variable

> + *	refresh rate support if the receiver supports it, ie. if the

> + *	"vrr_capable" property is true on the &drm_connector object. The

> + *	vertical front porch duration will be extended until page-flip or

> + *	timeout when enabled.

> + *

> + *	The minimum vertical front porch duration is defined as the vertical

> + *	front porch duration for the current mode.

> + *

> + *	The maximum vertical front porch duration is greater than or equal to

> + *	the minimum vertical front porch duration. The duration is derived

> + *	from the minimum supported variable refresh rate for the connector.

> + *

> + *	The driver may place further restrictions within these minimum

> + *	and maximum bounds.

> + *

> + *	The semantics for the vertical blank timestamp differ when

> + *	variable refresh rate is active. The vertical blank timestamp

> + *	is defined to be an estimate using the current mode's fixed

> + *	refresh rate timings. The semantics for the page-flip event

> + *	timestamp remain the same.

> + */

> +

>  /**

>   * drm_connector_attach_vrr_capable_property - creates the

>   * vrr_capable property

>
On 11/12/18 11:12 AM, Wentland, Harry wrote:
> On 2018-11-08 9:43 a.m., Nicholas Kazlauskas wrote:

>> These include the drm_connector 'vrr_capable' and the drm_crtc

>> 'vrr_enabled' properties.

>>

>> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>

>> Cc: Harry Wentland <harry.wentland@amd.com>

>> Cc: Manasi Navare <manasi.d.navare@intel.com>

>> Cc: Pekka Paalanen <ppaalanen@gmail.com>

>> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>

>> Cc: Michel Dänzer <michel@daenzer.net>

> 

> Looks good. Whole series is

> Reviewed-by: Harry Wentland <harry.wentland@amd.com>

> 

> How are we with the userspace patches? We should probably hold off pushing the kernel patches until the userspace work is all reviewed.

> 

> Harry


Thanks for the review.

The xf86-video-amdgpu patches have been reviewed and the mesa patches 
have been partially reviewed.

Nicholas Kazlauskas

> 

>> ---

>>   Documentation/gpu/drm-kms.rst   |  7 ++++

>>   drivers/gpu/drm/drm_connector.c | 68 +++++++++++++++++++++++++++++++++

>>   2 files changed, 75 insertions(+)

>>

>> diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst

>> index 4b1501b4835b..8da2a178cf85 100644

>> --- a/Documentation/gpu/drm-kms.rst

>> +++ b/Documentation/gpu/drm-kms.rst

>> @@ -575,6 +575,13 @@ Explicit Fencing Properties

>>   .. kernel-doc:: drivers/gpu/drm/drm_atomic_uapi.c

>>      :doc: explicit fencing properties

>>   

>> +

>> +Variable Refresh Properties

>> +---------------------------

>> +

>> +.. kernel-doc:: drivers/gpu/drm/drm_connector.c

>> +   :doc: Variable refresh properties

>> +

>>   Existing KMS Properties

>>   -----------------------

>>   

>> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c

>> index 49290060ab7b..0e4287461997 100644

>> --- a/drivers/gpu/drm/drm_connector.c

>> +++ b/drivers/gpu/drm/drm_connector.c

>> @@ -1255,6 +1255,74 @@ int drm_mode_create_scaling_mode_property(struct drm_device *dev)

>>   }

>>   EXPORT_SYMBOL(drm_mode_create_scaling_mode_property);

>>   

>> +/**

>> + * DOC: Variable refresh properties

>> + *

>> + * Variable refresh rate capable displays can dynamically adjust their

>> + * refresh rate by extending the duration of their vertical front porch

>> + * until page flip or timeout occurs. This can reduce or remove stuttering

>> + * and latency in scenarios where the page flip does not align with the

>> + * vblank interval.

>> + *

>> + * An example scenario would be an application flipping at a constant rate

>> + * of 48Hz on a 60Hz display. The page flip will frequently miss the vblank

>> + * interval and the same contents will be displayed twice. This can be

>> + * observed as stuttering for content with motion.

>> + *

>> + * If variable refresh rate was active on a display that supported a

>> + * variable refresh range from 35Hz to 60Hz no stuttering would be observable

>> + * for the example scenario. The minimum supported variable refresh rate of

>> + * 35Hz is below the page flip frequency and the vertical front porch can

>> + * be extended until the page flip occurs. The vblank interval will be

>> + * directly aligned to the page flip rate.

>> + *

>> + * Not all userspace content is suitable for use with variable refresh rate.

>> + * Large and frequent changes in vertical front porch duration may worsen

>> + * perceived stuttering for input sensitive applications.

>> + *

>> + * Panel brightness will also vary with vertical front porch duration. Some

>> + * panels may have noticeable differences in brightness between the minimum

>> + * vertical front porch duration and the maximum vertical front porch duration.

>> + * Large and frequent changes in vertical front porch duration may produce

>> + * observable flickering for such panels.

>> + *

>> + * Userspace control for variable refresh rate is supported via properties

>> + * on the &drm_connector and &drm_crtc objects.

>> + *

>> + * "vrr_capable":

>> + *	Optional &drm_connector boolean property that drivers should attach

>> + *	with drm_connector_attach_vrr_capable_property() on connectors that

>> + *	could support variable refresh rates. Drivers should update the

>> + *	property value by calling drm_connector_set_vrr_capable_property().

>> + *

>> + *	Absence of the property should indicate absence of support.

>> + *

>> + * "vrr_enabled":

>> + *	Default &drm_crtc boolean property that notifies the driver that the

>> + *	content on the CRTC is suitable for variable refresh rate presentation.

>> + *	The driver will take this property as a hint to enable variable

>> + *	refresh rate support if the receiver supports it, ie. if the

>> + *	"vrr_capable" property is true on the &drm_connector object. The

>> + *	vertical front porch duration will be extended until page-flip or

>> + *	timeout when enabled.

>> + *

>> + *	The minimum vertical front porch duration is defined as the vertical

>> + *	front porch duration for the current mode.

>> + *

>> + *	The maximum vertical front porch duration is greater than or equal to

>> + *	the minimum vertical front porch duration. The duration is derived

>> + *	from the minimum supported variable refresh rate for the connector.

>> + *

>> + *	The driver may place further restrictions within these minimum

>> + *	and maximum bounds.

>> + *

>> + *	The semantics for the vertical blank timestamp differ when

>> + *	variable refresh rate is active. The vertical blank timestamp

>> + *	is defined to be an estimate using the current mode's fixed

>> + *	refresh rate timings. The semantics for the page-flip event

>> + *	timestamp remain the same.

>> + */

>> +

>>   /**

>>    * drm_connector_attach_vrr_capable_property - creates the

>>    * vrr_capable property

>>
On 2018-11-12 12:05 p.m., Kazlauskas, Nicholas wrote:
> On 11/12/18 11:12 AM, Wentland, Harry wrote:

>> On 2018-11-08 9:43 a.m., Nicholas Kazlauskas wrote:

>>> These include the drm_connector 'vrr_capable' and the drm_crtc

>>> 'vrr_enabled' properties.

>>>

>>> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>

>>> Cc: Harry Wentland <harry.wentland@amd.com>

>>> Cc: Manasi Navare <manasi.d.navare@intel.com>

>>> Cc: Pekka Paalanen <ppaalanen@gmail.com>

>>> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>

>>> Cc: Michel Dänzer <michel@daenzer.net>

>>

>> Looks good. Whole series is

>> Reviewed-by: Harry Wentland <harry.wentland@amd.com>

>>

>> How are we with the userspace patches? We should probably hold off pushing the kernel patches until the userspace work is all reviewed.

>>

>> Harry

> 

> Thanks for the review.

> 

> The xf86-video-amdgpu patches have been reviewed and the mesa patches 

> have been partially reviewed.

> 


Alex, Michel,

how do we merge changes like this that provide a kernel API that goes together with userspace changes?

I imagine we'd want to get the kernel changes in first, and then merge the xf86-video-amdgpu and mesa changes. Please correct me if I'm wrong. Any objections to getting this merged via the usual amd-stg?

Thanks,
Harry


> Nicholas Kazlauskas

> 

>>

>>> ---

>>>   Documentation/gpu/drm-kms.rst   |  7 ++++

>>>   drivers/gpu/drm/drm_connector.c | 68 +++++++++++++++++++++++++++++++++

>>>   2 files changed, 75 insertions(+)

>>>

>>> diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst

>>> index 4b1501b4835b..8da2a178cf85 100644

>>> --- a/Documentation/gpu/drm-kms.rst

>>> +++ b/Documentation/gpu/drm-kms.rst

>>> @@ -575,6 +575,13 @@ Explicit Fencing Properties

>>>   .. kernel-doc:: drivers/gpu/drm/drm_atomic_uapi.c

>>>      :doc: explicit fencing properties

>>>   

>>> +

>>> +Variable Refresh Properties

>>> +---------------------------

>>> +

>>> +.. kernel-doc:: drivers/gpu/drm/drm_connector.c

>>> +   :doc: Variable refresh properties

>>> +

>>>   Existing KMS Properties

>>>   -----------------------

>>>   

>>> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c

>>> index 49290060ab7b..0e4287461997 100644

>>> --- a/drivers/gpu/drm/drm_connector.c

>>> +++ b/drivers/gpu/drm/drm_connector.c

>>> @@ -1255,6 +1255,74 @@ int drm_mode_create_scaling_mode_property(struct drm_device *dev)

>>>   }

>>>   EXPORT_SYMBOL(drm_mode_create_scaling_mode_property);

>>>   

>>> +/**

>>> + * DOC: Variable refresh properties

>>> + *

>>> + * Variable refresh rate capable displays can dynamically adjust their

>>> + * refresh rate by extending the duration of their vertical front porch

>>> + * until page flip or timeout occurs. This can reduce or remove stuttering

>>> + * and latency in scenarios where the page flip does not align with the

>>> + * vblank interval.

>>> + *

>>> + * An example scenario would be an application flipping at a constant rate

>>> + * of 48Hz on a 60Hz display. The page flip will frequently miss the vblank

>>> + * interval and the same contents will be displayed twice. This can be

>>> + * observed as stuttering for content with motion.

>>> + *

>>> + * If variable refresh rate was active on a display that supported a

>>> + * variable refresh range from 35Hz to 60Hz no stuttering would be observable

>>> + * for the example scenario. The minimum supported variable refresh rate of

>>> + * 35Hz is below the page flip frequency and the vertical front porch can

>>> + * be extended until the page flip occurs. The vblank interval will be

>>> + * directly aligned to the page flip rate.

>>> + *

>>> + * Not all userspace content is suitable for use with variable refresh rate.

>>> + * Large and frequent changes in vertical front porch duration may worsen

>>> + * perceived stuttering for input sensitive applications.

>>> + *

>>> + * Panel brightness will also vary with vertical front porch duration. Some

>>> + * panels may have noticeable differences in brightness between the minimum

>>> + * vertical front porch duration and the maximum vertical front porch duration.

>>> + * Large and frequent changes in vertical front porch duration may produce

>>> + * observable flickering for such panels.

>>> + *

>>> + * Userspace control for variable refresh rate is supported via properties

>>> + * on the &drm_connector and &drm_crtc objects.

>>> + *

>>> + * "vrr_capable":

>>> + *	Optional &drm_connector boolean property that drivers should attach

>>> + *	with drm_connector_attach_vrr_capable_property() on connectors that

>>> + *	could support variable refresh rates. Drivers should update the

>>> + *	property value by calling drm_connector_set_vrr_capable_property().

>>> + *

>>> + *	Absence of the property should indicate absence of support.

>>> + *

>>> + * "vrr_enabled":

>>> + *	Default &drm_crtc boolean property that notifies the driver that the

>>> + *	content on the CRTC is suitable for variable refresh rate presentation.

>>> + *	The driver will take this property as a hint to enable variable

>>> + *	refresh rate support if the receiver supports it, ie. if the

>>> + *	"vrr_capable" property is true on the &drm_connector object. The

>>> + *	vertical front porch duration will be extended until page-flip or

>>> + *	timeout when enabled.

>>> + *

>>> + *	The minimum vertical front porch duration is defined as the vertical

>>> + *	front porch duration for the current mode.

>>> + *

>>> + *	The maximum vertical front porch duration is greater than or equal to

>>> + *	the minimum vertical front porch duration. The duration is derived

>>> + *	from the minimum supported variable refresh rate for the connector.

>>> + *

>>> + *	The driver may place further restrictions within these minimum

>>> + *	and maximum bounds.

>>> + *

>>> + *	The semantics for the vertical blank timestamp differ when

>>> + *	variable refresh rate is active. The vertical blank timestamp

>>> + *	is defined to be an estimate using the current mode's fixed

>>> + *	refresh rate timings. The semantics for the page-flip event

>>> + *	timestamp remain the same.

>>> + */

>>> +

>>>   /**

>>>    * drm_connector_attach_vrr_capable_property - creates the

>>>    * vrr_capable property

>>>

>
On 2018-11-26 10:49 p.m., Wentland, Harry wrote:
> On 2018-11-12 12:05 p.m., Kazlauskas, Nicholas wrote:
>> On 11/12/18 11:12 AM, Wentland, Harry wrote:
>>> On 2018-11-08 9:43 a.m., Nicholas Kazlauskas wrote:
>>>> These include the drm_connector 'vrr_capable' and the drm_crtc
>>>> 'vrr_enabled' properties.
>>>>
>>>> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
>>>> Cc: Harry Wentland <harry.wentland@amd.com>
>>>> Cc: Manasi Navare <manasi.d.navare@intel.com>
>>>> Cc: Pekka Paalanen <ppaalanen@gmail.com>
>>>> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
>>>> Cc: Michel Dänzer <michel@daenzer.net>
>>>
>>> Looks good. Whole series is
>>> Reviewed-by: Harry Wentland <harry.wentland@amd.com>
>>>
>>> How are we with the userspace patches? We should probably hold off pushing the kernel patches until the userspace work is all reviewed.
>>>
>>> Harry
>>
>> Thanks for the review.
>>
>> The xf86-video-amdgpu patches have been reviewed and the mesa patches 
>> have been partially reviewed.
> 
> Alex, Michel,
> 
> how do we merge changes like this that provide a kernel API that goes
> together with userspace changes?
> 
> I imagine we'd want to get the kernel changes in first, and then merge
> the xf86-video-amdgpu and mesa changes.

Yeah, that's how it's usually done.


> Any objections to getting this merged via the usual amd-stg?

None from me.
On Mon, Nov 12, 2018 at 04:12:10PM +0000, Wentland, Harry wrote:
> On 2018-11-08 9:43 a.m., Nicholas Kazlauskas wrote:
> > These include the drm_connector 'vrr_capable' and the drm_crtc
> > 'vrr_enabled' properties.
> > 
> > Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
> > Cc: Harry Wentland <harry.wentland@amd.com>
> > Cc: Manasi Navare <manasi.d.navare@intel.com>
> > Cc: Pekka Paalanen <ppaalanen@gmail.com>
> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > Cc: Michel Dänzer <michel@daenzer.net>
> 
> Looks good. Whole series is
> Reviewed-by: Harry Wentland <harry.wentland@amd.com>
> 
> How are we with the userspace patches? We should probably hold off
> pushing the kernel patches until the userspace work is all reviewed.

Do some igts exist for this too? Especially for tricky pieces of uapi
having a non-vendor reference code somewhere would be good, aside from
testing and all that.
-Daniel

> 
> Harry
> 
> > ---
> >  Documentation/gpu/drm-kms.rst   |  7 ++++
> >  drivers/gpu/drm/drm_connector.c | 68 +++++++++++++++++++++++++++++++++
> >  2 files changed, 75 insertions(+)
> > 
> > diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
> > index 4b1501b4835b..8da2a178cf85 100644
> > --- a/Documentation/gpu/drm-kms.rst
> > +++ b/Documentation/gpu/drm-kms.rst
> > @@ -575,6 +575,13 @@ Explicit Fencing Properties
> >  .. kernel-doc:: drivers/gpu/drm/drm_atomic_uapi.c
> >     :doc: explicit fencing properties
> >  
> > +
> > +Variable Refresh Properties
> > +---------------------------
> > +
> > +.. kernel-doc:: drivers/gpu/drm/drm_connector.c
> > +   :doc: Variable refresh properties
> > +
> >  Existing KMS Properties
> >  -----------------------
> >  
> > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > index 49290060ab7b..0e4287461997 100644
> > --- a/drivers/gpu/drm/drm_connector.c
> > +++ b/drivers/gpu/drm/drm_connector.c
> > @@ -1255,6 +1255,74 @@ int drm_mode_create_scaling_mode_property(struct drm_device *dev)
> >  }
> >  EXPORT_SYMBOL(drm_mode_create_scaling_mode_property);
> >  
> > +/**
> > + * DOC: Variable refresh properties
> > + *
> > + * Variable refresh rate capable displays can dynamically adjust their
> > + * refresh rate by extending the duration of their vertical front porch
> > + * until page flip or timeout occurs. This can reduce or remove stuttering
> > + * and latency in scenarios where the page flip does not align with the
> > + * vblank interval.
> > + *
> > + * An example scenario would be an application flipping at a constant rate
> > + * of 48Hz on a 60Hz display. The page flip will frequently miss the vblank
> > + * interval and the same contents will be displayed twice. This can be
> > + * observed as stuttering for content with motion.
> > + *
> > + * If variable refresh rate was active on a display that supported a
> > + * variable refresh range from 35Hz to 60Hz no stuttering would be observable
> > + * for the example scenario. The minimum supported variable refresh rate of
> > + * 35Hz is below the page flip frequency and the vertical front porch can
> > + * be extended until the page flip occurs. The vblank interval will be
> > + * directly aligned to the page flip rate.
> > + *
> > + * Not all userspace content is suitable for use with variable refresh rate.
> > + * Large and frequent changes in vertical front porch duration may worsen
> > + * perceived stuttering for input sensitive applications.
> > + *
> > + * Panel brightness will also vary with vertical front porch duration. Some
> > + * panels may have noticeable differences in brightness between the minimum
> > + * vertical front porch duration and the maximum vertical front porch duration.
> > + * Large and frequent changes in vertical front porch duration may produce
> > + * observable flickering for such panels.
> > + *
> > + * Userspace control for variable refresh rate is supported via properties
> > + * on the &drm_connector and &drm_crtc objects.
> > + *
> > + * "vrr_capable":
> > + *	Optional &drm_connector boolean property that drivers should attach
> > + *	with drm_connector_attach_vrr_capable_property() on connectors that
> > + *	could support variable refresh rates. Drivers should update the
> > + *	property value by calling drm_connector_set_vrr_capable_property().
> > + *
> > + *	Absence of the property should indicate absence of support.
> > + *
> > + * "vrr_enabled":
> > + *	Default &drm_crtc boolean property that notifies the driver that the
> > + *	content on the CRTC is suitable for variable refresh rate presentation.
> > + *	The driver will take this property as a hint to enable variable
> > + *	refresh rate support if the receiver supports it, ie. if the
> > + *	"vrr_capable" property is true on the &drm_connector object. The
> > + *	vertical front porch duration will be extended until page-flip or
> > + *	timeout when enabled.
> > + *
> > + *	The minimum vertical front porch duration is defined as the vertical
> > + *	front porch duration for the current mode.
> > + *
> > + *	The maximum vertical front porch duration is greater than or equal to
> > + *	the minimum vertical front porch duration. The duration is derived
> > + *	from the minimum supported variable refresh rate for the connector.
> > + *
> > + *	The driver may place further restrictions within these minimum
> > + *	and maximum bounds.
> > + *
> > + *	The semantics for the vertical blank timestamp differ when
> > + *	variable refresh rate is active. The vertical blank timestamp
> > + *	is defined to be an estimate using the current mode's fixed
> > + *	refresh rate timings. The semantics for the page-flip event
> > + *	timestamp remain the same.
> > + */
> > +
> >  /**
> >   * drm_connector_attach_vrr_capable_property - creates the
> >   * vrr_capable property
> > 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
On 2018-11-27 4:22 a.m., Daniel Vetter wrote:
> On Mon, Nov 12, 2018 at 04:12:10PM +0000, Wentland, Harry wrote:

>> On 2018-11-08 9:43 a.m., Nicholas Kazlauskas wrote:

>>> These include the drm_connector 'vrr_capable' and the drm_crtc

>>> 'vrr_enabled' properties.

>>>

>>> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>

>>> Cc: Harry Wentland <harry.wentland@amd.com>

>>> Cc: Manasi Navare <manasi.d.navare@intel.com>

>>> Cc: Pekka Paalanen <ppaalanen@gmail.com>

>>> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>

>>> Cc: Michel Dänzer <michel@daenzer.net>

>>

>> Looks good. Whole series is

>> Reviewed-by: Harry Wentland <harry.wentland@amd.com>

>>

>> How are we with the userspace patches? We should probably hold off

>> pushing the kernel patches until the userspace work is all reviewed.

> 

> Do some igts exist for this too? Especially for tricky pieces of uapi

> having a non-vendor reference code somewhere would be good, aside from

> testing and all that.


Not yet, unfortunately, although it's on our list of things to do.

Harry

> -Daniel

> 

>>

>> Harry

>>

>>> ---

>>>  Documentation/gpu/drm-kms.rst   |  7 ++++

>>>  drivers/gpu/drm/drm_connector.c | 68 +++++++++++++++++++++++++++++++++

>>>  2 files changed, 75 insertions(+)

>>>

>>> diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst

>>> index 4b1501b4835b..8da2a178cf85 100644

>>> --- a/Documentation/gpu/drm-kms.rst

>>> +++ b/Documentation/gpu/drm-kms.rst

>>> @@ -575,6 +575,13 @@ Explicit Fencing Properties

>>>  .. kernel-doc:: drivers/gpu/drm/drm_atomic_uapi.c

>>>     :doc: explicit fencing properties

>>>  

>>> +

>>> +Variable Refresh Properties

>>> +---------------------------

>>> +

>>> +.. kernel-doc:: drivers/gpu/drm/drm_connector.c

>>> +   :doc: Variable refresh properties

>>> +

>>>  Existing KMS Properties

>>>  -----------------------

>>>  

>>> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c

>>> index 49290060ab7b..0e4287461997 100644

>>> --- a/drivers/gpu/drm/drm_connector.c

>>> +++ b/drivers/gpu/drm/drm_connector.c

>>> @@ -1255,6 +1255,74 @@ int drm_mode_create_scaling_mode_property(struct drm_device *dev)

>>>  }

>>>  EXPORT_SYMBOL(drm_mode_create_scaling_mode_property);

>>>  

>>> +/**

>>> + * DOC: Variable refresh properties

>>> + *

>>> + * Variable refresh rate capable displays can dynamically adjust their

>>> + * refresh rate by extending the duration of their vertical front porch

>>> + * until page flip or timeout occurs. This can reduce or remove stuttering

>>> + * and latency in scenarios where the page flip does not align with the

>>> + * vblank interval.

>>> + *

>>> + * An example scenario would be an application flipping at a constant rate

>>> + * of 48Hz on a 60Hz display. The page flip will frequently miss the vblank

>>> + * interval and the same contents will be displayed twice. This can be

>>> + * observed as stuttering for content with motion.

>>> + *

>>> + * If variable refresh rate was active on a display that supported a

>>> + * variable refresh range from 35Hz to 60Hz no stuttering would be observable

>>> + * for the example scenario. The minimum supported variable refresh rate of

>>> + * 35Hz is below the page flip frequency and the vertical front porch can

>>> + * be extended until the page flip occurs. The vblank interval will be

>>> + * directly aligned to the page flip rate.

>>> + *

>>> + * Not all userspace content is suitable for use with variable refresh rate.

>>> + * Large and frequent changes in vertical front porch duration may worsen

>>> + * perceived stuttering for input sensitive applications.

>>> + *

>>> + * Panel brightness will also vary with vertical front porch duration. Some

>>> + * panels may have noticeable differences in brightness between the minimum

>>> + * vertical front porch duration and the maximum vertical front porch duration.

>>> + * Large and frequent changes in vertical front porch duration may produce

>>> + * observable flickering for such panels.

>>> + *

>>> + * Userspace control for variable refresh rate is supported via properties

>>> + * on the &drm_connector and &drm_crtc objects.

>>> + *

>>> + * "vrr_capable":

>>> + *	Optional &drm_connector boolean property that drivers should attach

>>> + *	with drm_connector_attach_vrr_capable_property() on connectors that

>>> + *	could support variable refresh rates. Drivers should update the

>>> + *	property value by calling drm_connector_set_vrr_capable_property().

>>> + *

>>> + *	Absence of the property should indicate absence of support.

>>> + *

>>> + * "vrr_enabled":

>>> + *	Default &drm_crtc boolean property that notifies the driver that the

>>> + *	content on the CRTC is suitable for variable refresh rate presentation.

>>> + *	The driver will take this property as a hint to enable variable

>>> + *	refresh rate support if the receiver supports it, ie. if the

>>> + *	"vrr_capable" property is true on the &drm_connector object. The

>>> + *	vertical front porch duration will be extended until page-flip or

>>> + *	timeout when enabled.

>>> + *

>>> + *	The minimum vertical front porch duration is defined as the vertical

>>> + *	front porch duration for the current mode.

>>> + *

>>> + *	The maximum vertical front porch duration is greater than or equal to

>>> + *	the minimum vertical front porch duration. The duration is derived

>>> + *	from the minimum supported variable refresh rate for the connector.

>>> + *

>>> + *	The driver may place further restrictions within these minimum

>>> + *	and maximum bounds.

>>> + *

>>> + *	The semantics for the vertical blank timestamp differ when

>>> + *	variable refresh rate is active. The vertical blank timestamp

>>> + *	is defined to be an estimate using the current mode's fixed

>>> + *	refresh rate timings. The semantics for the page-flip event

>>> + *	timestamp remain the same.

>>> + */

>>> +

>>>  /**

>>>   * drm_connector_attach_vrr_capable_property - creates the

>>>   * vrr_capable property

>>>

>> _______________________________________________

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>> dri-devel@lists.freedesktop.org

>> https://lists.freedesktop.org/mailman/listinfo/dri-devel

>