From 803f7f5398fc73ed9c5229ff9f9758591739d1ad Mon Sep 17 00:00:00 2001
From: Sil Vilerino <sivileri@microsoft.com>
Date: Thu, 7 Mar 2024 08:01:54 -0500
Subject: [PATCH] d3d12: Video Encode - Add driver workaround for rate control
 reconfiguration

Adds a driver workaround for IHVs actually supporting rate control
reconfiguration but not reporting it in the DX12 driver support flags,
and later having crashes/hangs in the driver when the rate control
reconfiguration happens using the fallback method that includes re-creating
the encoder state and encoder heap objects upon new rate control params

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28075>
---
 src/gallium/drivers/d3d12/d3d12_video_enc.cpp | 29 +++++++++++++++----
 src/gallium/drivers/d3d12/d3d12_video_enc.h   | 11 +++++++
 2 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/src/gallium/drivers/d3d12/d3d12_video_enc.cpp b/src/gallium/drivers/d3d12/d3d12_video_enc.cpp
index c61c8e29853..1cc40dd949f 100644
--- a/src/gallium/drivers/d3d12/d3d12_video_enc.cpp
+++ b/src/gallium/drivers/d3d12/d3d12_video_enc.cpp
@@ -511,12 +511,18 @@ d3d12_video_encoder_reconfigure_encoder_objects(struct d3d12_video_encoder *pD3D
 
    // If on-the-fly reconfiguration happened without object recreation, set
    // D3D12_VIDEO_ENCODER_SEQUENCE_CONTROL_FLAG_*_CHANGED reconfiguration flags in EncodeFrame
-   if (rateControlChanged &&
-       ((pD3D12Enc->m_currentEncodeCapabilities.m_SupportFlags &
-         D3D12_VIDEO_ENCODER_SUPPORT_FLAG_RATE_CONTROL_RECONFIGURATION_AVAILABLE) !=
-        0 /*checking if the flag it's actually set*/) &&
-       (pD3D12Enc->m_fenceValue > 1) && (!reCreatedEncoder || !reCreatedEncoderHeap)) {
-      pD3D12Enc->m_currentEncodeConfig.m_seqFlags |= D3D12_VIDEO_ENCODER_SEQUENCE_CONTROL_FLAG_RATE_CONTROL_CHANGE;
+
+   // When driver workaround for rate control reconfig is active we cannot send to the driver the
+   // D3D12_VIDEO_ENCODER_SEQUENCE_CONTROL_FLAG_RATE_CONTROL_CHANGE since it's not actually reporting
+   // support for setting it.
+   if ((pD3D12Enc->driver_workarounds & d3d12_video_encoder_driver_workaround_rate_control_reconfig) == 0) {
+      if (rateControlChanged &&
+         ((pD3D12Enc->m_currentEncodeCapabilities.m_SupportFlags &
+            D3D12_VIDEO_ENCODER_SUPPORT_FLAG_RATE_CONTROL_RECONFIGURATION_AVAILABLE) !=
+         0 /*checking if the flag it's actually set*/) &&
+         (pD3D12Enc->m_fenceValue > 1) && (!reCreatedEncoder || !reCreatedEncoderHeap)) {
+         pD3D12Enc->m_currentEncodeConfig.m_seqFlags |= D3D12_VIDEO_ENCODER_SEQUENCE_CONTROL_FLAG_RATE_CONTROL_CHANGE;
+      }
    }
 
    if (slicesChanged &&
@@ -1376,6 +1382,17 @@ bool d3d12_video_encoder_query_d3d12_driver_caps(struct d3d12_video_encoder *pD3
          return false;
       }
    }
+
+   // Workaround for drivers supporting rate control reconfiguration but not reporting it
+   // and having issues with encoder state/heap objects recreation
+   if (pD3D12Enc->m_pD3D12Screen->vendor_id == 0x8086 /* HW_VENDOR_INTEL */) {
+      // If IHV driver doesn't report reconfiguration, force doing the reconfiguration without object recreation
+      if ((capEncoderSupportData1.SupportFlags & D3D12_VIDEO_ENCODER_SUPPORT_FLAG_RATE_CONTROL_RECONFIGURATION_AVAILABLE) == 0) {
+         pD3D12Enc->driver_workarounds |= d3d12_video_encoder_driver_workaround_rate_control_reconfig;
+         capEncoderSupportData1.SupportFlags |= D3D12_VIDEO_ENCODER_SUPPORT_FLAG_RATE_CONTROL_RECONFIGURATION_AVAILABLE;
+      }
+   }
+
    pD3D12Enc->m_currentEncodeCapabilities.m_SupportFlags    = capEncoderSupportData1.SupportFlags;
    pD3D12Enc->m_currentEncodeCapabilities.m_ValidationFlags = capEncoderSupportData1.ValidationFlags;
    return true;
diff --git a/src/gallium/drivers/d3d12/d3d12_video_enc.h b/src/gallium/drivers/d3d12/d3d12_video_enc.h
index 2c1bb72ff56..64bbe062f2e 100644
--- a/src/gallium/drivers/d3d12/d3d12_video_enc.h
+++ b/src/gallium/drivers/d3d12/d3d12_video_enc.h
@@ -356,6 +356,15 @@ struct EncodedBitstreamResolvedMetadata
    struct d3d12_fence m_FenceData;
 };
 
+enum d3d12_video_encoder_driver_workarounds
+{
+   d3d12_video_encoder_driver_workaround_none = 0x0,
+   // Workaround for drivers supporting rate control reconfiguration but not reporting it
+   // and having issues with encoder state/heap objects recreation
+   d3d12_video_encoder_driver_workaround_rate_control_reconfig = 0x1,
+};
+DEFINE_ENUM_FLAG_OPERATORS(d3d12_video_encoder_driver_workarounds);
+
 struct d3d12_video_encoder
 {
    struct pipe_video_codec base = {};
@@ -363,6 +372,8 @@ struct d3d12_video_encoder
    struct d3d12_screen *   m_pD3D12Screen = nullptr;
    UINT max_quality_levels = 1;
 
+   enum d3d12_video_encoder_driver_workarounds driver_workarounds = d3d12_video_encoder_driver_workaround_none;
+
    ///
    /// D3D12 objects and context info
    ///