diff mbox series

[v5,2/3] drm/i915: Lookup and attach ACPI device node for connectors

Message ID 20191220200353.252399-2-rajatja@google.com (mailing list archive)
State New, archived
Headers show
Series [v5,1/3] drm/i915: Move the code to populate ACPI device ID into intel_acpi | expand

Commit Message

Rajat Jain Dec. 20, 2019, 8:03 p.m. UTC
Lookup and attach ACPI nodes for intel connectors. The lookup is done
in compliance with ACPI Spec 6.3
https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf
(Ref: Pages 1119 - 1123).

This can be useful for any connector specific platform properties. (This
will be used for privacy screen in next patch).

Signed-off-by: Rajat Jain <rajatja@google.com>
---
v5: same as v4
v4: Same as v3
v3: fold the code into existing acpi_device_id_update() function
v2: formed by splitting the original patch into ACPI lookup, and privacy
    screen property. Also move it into i915 now that I found existing code
    in i915 that can be re-used.

 drivers/gpu/drm/i915/display/intel_acpi.c     | 24 +++++++++++++++++++
 .../drm/i915/display/intel_display_types.h    |  3 +++
 drivers/gpu/drm/i915/display/intel_dp.c       |  3 +++
 3 files changed, 30 insertions(+)

Comments

Jani Nikula Jan. 24, 2020, 11:37 a.m. UTC | #1
On Fri, 20 Dec 2019, Rajat Jain <rajatja@google.com> wrote:
> Lookup and attach ACPI nodes for intel connectors. The lookup is done
> in compliance with ACPI Spec 6.3
> https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf
> (Ref: Pages 1119 - 1123).
>
> This can be useful for any connector specific platform properties. (This
> will be used for privacy screen in next patch).
>
> Signed-off-by: Rajat Jain <rajatja@google.com>
> ---
> v5: same as v4
> v4: Same as v3
> v3: fold the code into existing acpi_device_id_update() function
> v2: formed by splitting the original patch into ACPI lookup, and privacy
>     screen property. Also move it into i915 now that I found existing code
>     in i915 that can be re-used.
>
>  drivers/gpu/drm/i915/display/intel_acpi.c     | 24 +++++++++++++++++++
>  .../drm/i915/display/intel_display_types.h    |  3 +++
>  drivers/gpu/drm/i915/display/intel_dp.c       |  3 +++
>  3 files changed, 30 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_acpi.c b/drivers/gpu/drm/i915/display/intel_acpi.c
> index e21fb14d5e07..101a56c08996 100644
> --- a/drivers/gpu/drm/i915/display/intel_acpi.c
> +++ b/drivers/gpu/drm/i915/display/intel_acpi.c
> @@ -222,11 +222,23 @@ static u32 acpi_display_type(struct intel_connector *connector)
>  	return display_type;
>  }
>  
> +/*
> + * Ref: ACPI Spec 6.3
> + * https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf
> + * Pages 1119 - 1123 describe, what I believe, a standard way of
> + * identifying / addressing "display panels" in the ACPI. It provides
> + * a way for the ACPI to define devices for the display panels attached
> + * to the system. It thus provides a way for the BIOS to export any panel
> + * specific properties to the system via ACPI (like device trees).
> + */
>  void intel_acpi_device_id_update(struct drm_i915_private *dev_priv)
>  {
>  	struct drm_device *drm_dev = &dev_priv->drm;
>  	struct intel_connector *connector;
>  	struct drm_connector_list_iter conn_iter;
> +	struct device *dev = &drm_dev->pdev->dev;

Hmm, already pushed patch 1 with the unfortunate "drm_dev" local. We use
"dev" for struct drm_device * and almost never use struct device.

> +	struct acpi_device *conn_dev;
> +	u64 conn_addr;
>  	u8 display_index[16] = {};
>  
>  	/* Populate the ACPI IDs for all connectors for a given drm_device */
> @@ -242,6 +254,18 @@ void intel_acpi_device_id_update(struct drm_i915_private *dev_priv)
>  		device_id |= display_index[type]++ << ACPI_DISPLAY_INDEX_SHIFT;
>  
>  		connector->acpi_device_id = device_id;
> +
> +		/* Build the _ADR to look for */
> +		conn_addr = device_id | ACPI_DEVICE_ID_SCHEME |
> +				ACPI_BIOS_CAN_DETECT;
> +
> +		DRM_DEV_INFO(dev, "Checking connector ACPI node at _ADR=%llX\n",
> +			     conn_addr);

This is more than a little verbose. One line of INFO level dmesg for
every connector at boot and at resume.

Please use the new drm_dbg_kms() macro for this.

> +
> +		/* Look up the connector device, under the PCI device */
> +		conn_dev = acpi_find_child_device(ACPI_COMPANION(dev),
> +						  conn_addr, false);
> +		connector->acpi_handle = conn_dev ? conn_dev->handle : NULL;

acpi_device_handle(conn_dev)

>  	}
>  	drm_connector_list_iter_end(&conn_iter);
>  }
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 1a7334dbe802..0a4a04116091 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -407,6 +407,9 @@ struct intel_connector {
>  	/* ACPI device id for ACPI and driver cooperation */
>  	u32 acpi_device_id;
>  
> +	/* ACPI handle corresponding to this connector display, if found */
> +	void *acpi_handle;
> +

The type is acpi_handle. It's none of our business to know what the
underlying type is.

>  	/* Reads out the current hw, returning true if the connector is enabled
>  	 * and active (i.e. dpms ON state). */
>  	bool (*get_hw_state)(struct intel_connector *);
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index b05b2191b919..93cece8e2516 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -45,6 +45,7 @@
>  #include "i915_debugfs.h"
>  #include "i915_drv.h"
>  #include "i915_trace.h"
> +#include "intel_acpi.h"
>  #include "intel_atomic.h"
>  #include "intel_audio.h"
>  #include "intel_connector.h"
> @@ -6623,6 +6624,8 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect
>  
>  		connector->state->scaling_mode = DRM_MODE_SCALE_ASPECT;
>  
> +		/* Lookup the ACPI node corresponding to the connector */
> +		intel_acpi_device_id_update(dev_priv);

Auch, this is problematic. It iterates all connectors, for every DP
connector being added. In the middle of registering all connectors.

From the POV of this patch alone, this is also unnecessary. This gets
called via intel_opregion_register() after all connectors have been
registered.

I am aware it's not enough for your next patch, because it will need the
acpi handle right here.

I'm wondering if we need to maintain display_index[] in struct
drm_i915_private, and update that as connectors get added instead of all
at once in the end. connector->acpi_device_id never changes, does it,
even though we keep updating it?

BR,
Jani.


>  	}
>  }
Rajat Jain Jan. 24, 2020, 8:23 p.m. UTC | #2
Hi Jani,

Thank you for the review. Please see inline.

On Fri, Jan 24, 2020 at 3:37 AM Jani Nikula <jani.nikula@linux.intel.com> wrote:
>
> On Fri, 20 Dec 2019, Rajat Jain <rajatja@google.com> wrote:
> > Lookup and attach ACPI nodes for intel connectors. The lookup is done
> > in compliance with ACPI Spec 6.3
> > https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf
> > (Ref: Pages 1119 - 1123).
> >
> > This can be useful for any connector specific platform properties. (This
> > will be used for privacy screen in next patch).
> >
> > Signed-off-by: Rajat Jain <rajatja@google.com>
> > ---
> > v5: same as v4
> > v4: Same as v3
> > v3: fold the code into existing acpi_device_id_update() function
> > v2: formed by splitting the original patch into ACPI lookup, and privacy
> >     screen property. Also move it into i915 now that I found existing code
> >     in i915 that can be re-used.
> >
> >  drivers/gpu/drm/i915/display/intel_acpi.c     | 24 +++++++++++++++++++
> >  .../drm/i915/display/intel_display_types.h    |  3 +++
> >  drivers/gpu/drm/i915/display/intel_dp.c       |  3 +++
> >  3 files changed, 30 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_acpi.c b/drivers/gpu/drm/i915/display/intel_acpi.c
> > index e21fb14d5e07..101a56c08996 100644
> > --- a/drivers/gpu/drm/i915/display/intel_acpi.c
> > +++ b/drivers/gpu/drm/i915/display/intel_acpi.c
> > @@ -222,11 +222,23 @@ static u32 acpi_display_type(struct intel_connector *connector)
> >       return display_type;
> >  }
> >
> > +/*
> > + * Ref: ACPI Spec 6.3
> > + * https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf
> > + * Pages 1119 - 1123 describe, what I believe, a standard way of
> > + * identifying / addressing "display panels" in the ACPI. It provides
> > + * a way for the ACPI to define devices for the display panels attached
> > + * to the system. It thus provides a way for the BIOS to export any panel
> > + * specific properties to the system via ACPI (like device trees).
> > + */
> >  void intel_acpi_device_id_update(struct drm_i915_private *dev_priv)
> >  {
> >       struct drm_device *drm_dev = &dev_priv->drm;
> >       struct intel_connector *connector;
> >       struct drm_connector_list_iter conn_iter;
> > +     struct device *dev = &drm_dev->pdev->dev;
>
> Hmm, already pushed patch 1 with the unfortunate "drm_dev" local. We use
> "dev" for struct drm_device * and almost never use struct device.

Sorry, I did not know. I'll send an independent fixup patch for patch
1 on top of drm-intel-next-queued (or let me know if you want to
handle it). I will also change this patch to rename the variable.

>
> > +     struct acpi_device *conn_dev;
> > +     u64 conn_addr;
> >       u8 display_index[16] = {};
> >
> >       /* Populate the ACPI IDs for all connectors for a given drm_device */
> > @@ -242,6 +254,18 @@ void intel_acpi_device_id_update(struct drm_i915_private *dev_priv)
> >               device_id |= display_index[type]++ << ACPI_DISPLAY_INDEX_SHIFT;
> >
> >               connector->acpi_device_id = device_id;
> > +
> > +             /* Build the _ADR to look for */
> > +             conn_addr = device_id | ACPI_DEVICE_ID_SCHEME |
> > +                             ACPI_BIOS_CAN_DETECT;
> > +
> > +             DRM_DEV_INFO(dev, "Checking connector ACPI node at _ADR=%llX\n",
> > +                          conn_addr);
>
> This is more than a little verbose. One line of INFO level dmesg for
> every connector at boot and at resume.
>
> Please use the new drm_dbg_kms() macro for this.

Will do.

>
> > +
> > +             /* Look up the connector device, under the PCI device */
> > +             conn_dev = acpi_find_child_device(ACPI_COMPANION(dev),
> > +                                               conn_addr, false);
> > +             connector->acpi_handle = conn_dev ? conn_dev->handle : NULL;
>
> acpi_device_handle(conn_dev)
>

Will do.


> >       }
> >       drm_connector_list_iter_end(&conn_iter);
> >  }
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> > index 1a7334dbe802..0a4a04116091 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > @@ -407,6 +407,9 @@ struct intel_connector {
> >       /* ACPI device id for ACPI and driver cooperation */
> >       u32 acpi_device_id;
> >
> > +     /* ACPI handle corresponding to this connector display, if found */
> > +     void *acpi_handle;
> > +
>
> The type is acpi_handle. It's none of our business to know what the
> underlying type is.

Will do.

>
> >       /* Reads out the current hw, returning true if the connector is enabled
> >        * and active (i.e. dpms ON state). */
> >       bool (*get_hw_state)(struct intel_connector *);
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > index b05b2191b919..93cece8e2516 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -45,6 +45,7 @@
> >  #include "i915_debugfs.h"
> >  #include "i915_drv.h"
> >  #include "i915_trace.h"
> > +#include "intel_acpi.h"
> >  #include "intel_atomic.h"
> >  #include "intel_audio.h"
> >  #include "intel_connector.h"
> > @@ -6623,6 +6624,8 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect
> >
> >               connector->state->scaling_mode = DRM_MODE_SCALE_ASPECT;
> >
> > +             /* Lookup the ACPI node corresponding to the connector */
> > +             intel_acpi_device_id_update(dev_priv);
>
> Auch, this is problematic. It iterates all connectors, for every DP
> connector being added. In the middle of registering all connectors.
>
> From the POV of this patch alone, this is also unnecessary. This gets
> called via intel_opregion_register() after all connectors have been
> registered.
>
> I am aware it's not enough for your next patch, because it will need the
> acpi handle right here.
>
> I'm wondering if we need to maintain display_index[] in struct
> drm_i915_private, and update that as connectors get added instead of all
> at once in the end.

Sure, I can do that.

> connector->acpi_device_id never changes, does it,
> even though we keep updating it?

This is the part I am not so sure about - I hypothesized that theory
because of the current behavior in code (i.e. it is getting updated in
intel_opregion_resume() path). May be it does not change, I was not
sure, so I did not want to create any regression in the intel_opregion
code that I did not understand. I tried on my system and as far as I
could experiment, I did not see it changing. Please let me know if you
would like me to change my code to:

1) Maintain drm_i915_private->display_index[] and update it as
connectors are added.
2) Remove the code to update it on every resume and while registering
the connector.

Thanks & Best Regards,

Rajat

>
> BR,
> Jani.
>
>
> >       }
> >  }
>
> --
> Jani Nikula, Intel Open Source Graphics Center
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_acpi.c b/drivers/gpu/drm/i915/display/intel_acpi.c
index e21fb14d5e07..101a56c08996 100644
--- a/drivers/gpu/drm/i915/display/intel_acpi.c
+++ b/drivers/gpu/drm/i915/display/intel_acpi.c
@@ -222,11 +222,23 @@  static u32 acpi_display_type(struct intel_connector *connector)
 	return display_type;
 }
 
+/*
+ * Ref: ACPI Spec 6.3
+ * https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf
+ * Pages 1119 - 1123 describe, what I believe, a standard way of
+ * identifying / addressing "display panels" in the ACPI. It provides
+ * a way for the ACPI to define devices for the display panels attached
+ * to the system. It thus provides a way for the BIOS to export any panel
+ * specific properties to the system via ACPI (like device trees).
+ */
 void intel_acpi_device_id_update(struct drm_i915_private *dev_priv)
 {
 	struct drm_device *drm_dev = &dev_priv->drm;
 	struct intel_connector *connector;
 	struct drm_connector_list_iter conn_iter;
+	struct device *dev = &drm_dev->pdev->dev;
+	struct acpi_device *conn_dev;
+	u64 conn_addr;
 	u8 display_index[16] = {};
 
 	/* Populate the ACPI IDs for all connectors for a given drm_device */
@@ -242,6 +254,18 @@  void intel_acpi_device_id_update(struct drm_i915_private *dev_priv)
 		device_id |= display_index[type]++ << ACPI_DISPLAY_INDEX_SHIFT;
 
 		connector->acpi_device_id = device_id;
+
+		/* Build the _ADR to look for */
+		conn_addr = device_id | ACPI_DEVICE_ID_SCHEME |
+				ACPI_BIOS_CAN_DETECT;
+
+		DRM_DEV_INFO(dev, "Checking connector ACPI node at _ADR=%llX\n",
+			     conn_addr);
+
+		/* Look up the connector device, under the PCI device */
+		conn_dev = acpi_find_child_device(ACPI_COMPANION(dev),
+						  conn_addr, false);
+		connector->acpi_handle = conn_dev ? conn_dev->handle : NULL;
 	}
 	drm_connector_list_iter_end(&conn_iter);
 }
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 1a7334dbe802..0a4a04116091 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -407,6 +407,9 @@  struct intel_connector {
 	/* ACPI device id for ACPI and driver cooperation */
 	u32 acpi_device_id;
 
+	/* ACPI handle corresponding to this connector display, if found */
+	void *acpi_handle;
+
 	/* Reads out the current hw, returning true if the connector is enabled
 	 * and active (i.e. dpms ON state). */
 	bool (*get_hw_state)(struct intel_connector *);
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index b05b2191b919..93cece8e2516 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -45,6 +45,7 @@ 
 #include "i915_debugfs.h"
 #include "i915_drv.h"
 #include "i915_trace.h"
+#include "intel_acpi.h"
 #include "intel_atomic.h"
 #include "intel_audio.h"
 #include "intel_connector.h"
@@ -6623,6 +6624,8 @@  intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect
 
 		connector->state->scaling_mode = DRM_MODE_SCALE_ASPECT;
 
+		/* Lookup the ACPI node corresponding to the connector */
+		intel_acpi_device_id_update(dev_priv);
 	}
 }