[PATCH v2] drm/dp: Add function to parse EDID descriptors for adaptive sync limits

Manasi Navare manasi.d.navare at intel.com
Mon Mar 2 20:09:53 UTC 2020


On Mon, Mar 02, 2020 at 09:15:27AM -0500, Kazlauskas, Nicholas wrote:
> On 2020-02-28 9:38 p.m., Manasi Navare wrote:
> >On Fri, Feb 28, 2020 at 01:18:45PM -0800, Manasi Navare wrote:
> >>On Thu, Jan 09, 2020 at 03:08:52PM +0200, Ville Syrjälä wrote:
> >>>On Tue, Jan 07, 2020 at 04:32:08PM -0800, Manasi Navare wrote:
> >>>>Adaptive Sync is a VESA feature so add a DRM core helper to parse
> >>>>the EDID's detailed descritors to obtain the adaptive sync monitor range.
> >>>>Store this info as part fo drm_display_info so it can be used
> >>>>across all drivers.
> >>>>This part of the code is stripped out of amdgpu's function
> >>>>amdgpu_dm_update_freesync_caps() to make it generic and be used
> >>>>across all DRM drivers
> >>>>
> >>>>v2:
> >>>>* Change vmin and vmax to use u8 (Ville)
> >>>>* Dont store pixel clock since that is just a max dotclock
> >>>>and not related to VRR mode (Manasi)
> >>>>
> >>>>Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >>>>Cc: Harry Wentland <harry.wentland at amd.com>
> >>>>Cc: Clinton A Taylor <clinton.a.taylor at intel.com>
> >>>>Cc: Nicholas Kazlauskas <nicholas.kazluaskas at amd.com>
> >>>>Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> 
> Hi Manasi, sorry for the delayed response on this one!
> 
> Few comments inline below:
> 
> >>>>---
> >>>>  drivers/gpu/drm/drm_edid.c  | 51 +++++++++++++++++++++++++++++++++++++
> >>>>  include/drm/drm_connector.h | 22 ++++++++++++++++
> >>>>  include/drm/drm_edid.h      |  2 ++
> >>>>  3 files changed, 75 insertions(+)
> >>>>
> >>>>diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> >>>>index 99769d6c9f84..52781a0e708b 100644
> >>>>--- a/drivers/gpu/drm/drm_edid.c
> >>>>+++ b/drivers/gpu/drm/drm_edid.c
> >>>>@@ -4880,6 +4880,54 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
> >>>>  	}
> >>>>  }
> >>>>+void drm_get_adaptive_sync_limits(struct drm_connector *connector,
> >>>>+				  const struct edid *edid)
> 
> Agree with other feedback here on making this static. We can move over
> amdgpu to just check the DRM reported caps after.
> 
> >>>>+{
> >>>>+	struct drm_display_info *info = &connector->display_info;
> >>>>+	const struct detailed_timing *timing;
> >>>>+	const struct detailed_non_pixel *data;
> >>>>+	const struct detailed_data_monitor_range *range;
> >>>
> >>>Needlessly wide scope for everything above.
> >>
> >>Ok will add this inside the for loop
> >>
> >>>
> >>>>+	int i;
> >>>>+
> >>>>+	/*
> >>>>+	 * Restrict Adaptive Sync only for dp and edp
> >>>>+	 */
> >>>>+	if (connector->connector_type != DRM_MODE_CONNECTOR_DisplayPort &&
> >>>>+	    connector->connector_type != DRM_MODE_CONNECTOR_eDP)
> >>>>+		return;
> 
> This probably doesn't need to be blocked here, this is just parsing the
> EDID.
> 
> >>>>+
> >>>>+	if (edid->version <= 1 && !(edid->version == 1 && edid->revision > 1))
> >>>>+		return;
> >>>
> >>>if (!version_greater(...))
> >>>	return;
> >>>
> >>>>+
> >>>>+	for (i = 0; i < 4; i++) {
> >>>
> >>>This should probably use for_each_detailed_block()
> >>
> >>Can you elaborate, I dont understand what you mean by using for_each_detailed_block()
> >>
> >>Manasi
> >
> >Does that mean:
> >I need to define drm_edid_get_vrr_range()  where i call drm_for_each_detailed_block((u8 * )edid, get_vrr_range, &vrr_min, &vrr_max)  but i need to access range   = &data->data.range; where
> >  data = &timing->data.other_data; inside get_vrr_range() how can I access range?
> >
> >Manasi
> 
> Wouldn't it look like:
> 
> drm_for_each_detailed_block((u8 *)edid, get_adaptive_sync_range,
> &info->adaptive_sync);

Yes but am still not sure how to access timing, data and range from the passed argumnet of edid, once
that is clear then yes I can just fill info->adaptive sync directly inside the function.

Manasi

> 
> Or something along those lines?
> 
> >
> >>
> >>>
> >>>>+		timing  = &edid->detailed_timings[i];
> >>>>+		data    = &timing->data.other_data;
> >>>>+		range   = &data->data.range;
> >>>>+		/*
> >>>>+		 * Check if monitor has continuous frequency mode
> >>>>+		 */
> >>>>+		if (data->type != EDID_DETAIL_MONITOR_RANGE)
> >
> >>>>+		/*
> >>>>+		 * Check for flag range limits only. If flag == 1 then
> >>>>+		 * no additional timing information provided.
> >>>>+		 * Default GTF, GTF Secondary curve and CVT are not
> >>>>+		 * supported
> >>>>+		 */
> >>>>+		if (range->flags != 1)
> >>>>+			continue;
> >>>>+
> >>>>+		info->adaptive_sync.min_vfreq = range->min_vfreq;
> >>>>+		info->adaptive_sync.max_vfreq = range->max_vfreq;
> >>>>+
> >>>>+		DRM_DEBUG_KMS("Adaptive Sync refresh rate range is %d Hz - %d Hz\n",
> >>>>+			      info->adaptive_sync.min_vfreq,
> >>>>+			      info->adaptive_sync.max_vfreq);
> >>>>+		break;
> >>>>+	}
> >>>>+}
> >>>>+EXPORT_SYMBOL(drm_get_adaptive_sync_limits);
> 
> Can drop this EXPORT since this is all in drm_edid.c.
> 
> >>>>+
> >>>>  /* A connector has no EDID information, so we've got no EDID to compute quirks from. Reset
> >>>>   * all of the values which would have been set from EDID
> >>>>   */
> >>>>@@ -4901,6 +4949,7 @@ drm_reset_display_info(struct drm_connector *connector)
> >>>>  	memset(&info->hdmi, 0, sizeof(info->hdmi));
> >>>>  	info->non_desktop = 0;
> >>>>+	memset(&info->adaptive_sync, 0, sizeof(info->adaptive_sync));
> >>>>  }
> >>>>  u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edid)
> >>>>@@ -4916,6 +4965,8 @@ u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edi
> >>>>  	info->non_desktop = !!(quirks & EDID_QUIRK_NON_DESKTOP);
> >>>>+	drm_get_adaptive_sync_limits(connector, edid);
> >>>>+
> >>>>  	DRM_DEBUG_KMS("non_desktop set to %d\n", info->non_desktop);
> >>>>  	if (edid->revision < 3)
> >>>>diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> >>>>index 221910948b37..77df404a2e01 100644
> >>>>--- a/include/drm/drm_connector.h
> >>>>+++ b/include/drm/drm_connector.h
> >>>>@@ -254,6 +254,23 @@ enum drm_panel_orientation {
> >>>>  	DRM_MODE_PANEL_ORIENTATION_RIGHT_UP,
> >>>>  };
> >>>>+/**
> >>>>+ * struct drm_adaptive_sync_info - Panel's Adaptive Sync capabilities for
> >>>>+ * &drm_display_info
> >>>>+ *
> >>>>+ * This struct is used to store a Panel's Adaptive Sync capabilities
> >>>>+ * as parsed from EDID's detailed monitor range descriptor block.
> >>>>+ *
> >>>>+ * @min_vfreq: This is the min supported refresh rate in Hz from
> >>>>+ *             EDID's detailed monitor range.
> >>>>+ * @max_vfreq: This is the max supported refresh rate in Hz from
> >>>>+ *             EDID's detailed monitor range
> >>>>+ */
> >>>>+struct drm_adaptive_sync_info {
> >>>>+	u8 min_vfreq;
> >>>>+	u8 max_vfreq;
> >>>>+};
> >>>>+
> >>>>  /*
> >>>>   * This is a consolidated colorimetry list supported by HDMI and
> >>>>   * DP protocol standard. The respective connectors will register
> >>>>@@ -465,6 +482,11 @@ struct drm_display_info {
> >>>>  	 * @non_desktop: Non desktop display (HMD).
> >>>>  	 */
> >>>>  	bool non_desktop;
> >>>>+
> >>>>+	/**
> >>>>+	 * @adaptive_sync: Adaptive Sync capabilities of the DP/eDP sink
> >>>>+	 */
> >>>>+	struct drm_adaptive_sync_info adaptive_sync;
> >>>>  };
> >>>>  int drm_display_info_set_bus_formats(struct drm_display_info *info,
> >>>>diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
> >>>>index f0b03d401c27..b9a230aa3e69 100644
> >>>>--- a/include/drm/drm_edid.h
> >>>>+++ b/include/drm/drm_edid.h
> >>>>@@ -503,4 +503,6 @@ void drm_edid_get_monitor_name(struct edid *edid, char *name,
> >>>>  struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
> >>>>  					   int hsize, int vsize, int fresh,
> >>>>  					   bool rb);
> >>>>+void drm_get_adaptive_sync_limits(struct drm_connector *connector,
> >>>>+				  const struct edid *edid);
> 
> Can drop this one as well.
> 
> Regards,
> Nicholas Kazlauskas
> 
> >>>>  #endif /* __DRM_EDID_H__ */
> >>>>-- 
> >>>>2.19.1
> >>>
> >>>-- 
> >>>Ville Syrjälä
> >>>Intel
> >>_______________________________________________
> >>dri-devel mailing list
> >>dri-devel at lists.freedesktop.org
> >>https://lists.freedesktop.org/mailman/listinfo/dri-devel
> >_______________________________________________
> >dri-devel mailing list
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> >https://lists.freedesktop.org/mailman/listinfo/dri-devel
> >
> 


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