[Intel-gfx] [PATCH v2 1/2] drm/dp: DRM DP helper for reading Ignore MSA from DPCD

[Manasi Navare]

DP sink device sets the Ignore MSA bit in its
DP_DOWNSTREAM_PORT_COUNT register to indicate its ability to
ignore the MSA video timing paramaters and its ability to support
seamless video timing change over a range of timing exposed by
DisplayID and EDID.
This is required for the sink to indicate that it is Adaptive sync
capable.

v2:
* Rename to describe what the function does (Jani Nikula)

Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Harry Wentland <harry.wentland at amd.com>
Cc: Nicholas Kazlauskas <Nicholas.Kazlauskas at amd.com>
Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
Reviewed-by: Harry Wentland <harry.wentland at amd.com>
---
 include/drm/drm_dp_helper.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 9d87cdf2740a..36655f3c83f8 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1315,6 +1315,14 @@ drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 			DP_ALTERNATE_SCRAMBLER_RESET_CAP;
 }
 
+/* Ignore MSA timing for Adaptive Sync support on DP 1.4 */
+static inline bool
+drm_dp_sink_can_do_video_without_timing_msa(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_DOWN_STREAM_PORT_COUNT] &
+		DP_MSA_TIMING_PAR_IGNORED;
+}
+
 /*
  * DisplayPort AUX channel
  */
-- 
2.19.1