From: jsg <jsg@openbsd.org>
Date: Mon, 25 Sep 2023 03:13:45 +0000 (+0000)
Subject: Revert "drm/amd: Disable S/G for APUs when 64GB or more host memory"
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=8011bb73c66d56ce49ac9d8ce185c385146f8a6d;p=openbsd

Revert "drm/amd: Disable S/G for APUs when 64GB or more host memory"

From Hamza Mahfooz
216eae7d7dea5fdd854d7decb44fcf3b719548a0 in linux-6.1.y/6.1.55
169ed4ece8373f02f10642eae5240e3d1ef5c038 in mainline linux
---

diff --git a/sys/dev/pci/drm/amd/amdgpu/amdgpu.h b/sys/dev/pci/drm/amd/amdgpu/amdgpu.h
index 6bd8895f3d4..49a995b8a59 100644
--- a/sys/dev/pci/drm/amd/amdgpu/amdgpu.h
+++ b/sys/dev/pci/drm/amd/amdgpu/amdgpu.h
@@ -1295,7 +1295,6 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
 void amdgpu_device_pci_config_reset(struct amdgpu_device *adev);
 int amdgpu_device_pci_reset(struct amdgpu_device *adev);
 bool amdgpu_device_need_post(struct amdgpu_device *adev);
-bool amdgpu_sg_display_supported(struct amdgpu_device *adev);
 bool amdgpu_device_pcie_dynamic_switching_supported(void);
 bool amdgpu_device_should_use_aspm(struct amdgpu_device *adev);
 bool amdgpu_device_aspm_support_quirk(void);
diff --git a/sys/dev/pci/drm/amd/amdgpu/amdgpu_device.c b/sys/dev/pci/drm/amd/amdgpu/amdgpu_device.c
index 803e2d9dc72..abb3001559e 100644
--- a/sys/dev/pci/drm/amd/amdgpu/amdgpu_device.c
+++ b/sys/dev/pci/drm/amd/amdgpu/amdgpu_device.c
@@ -1354,32 +1354,6 @@ bool amdgpu_device_need_post(struct amdgpu_device *adev)
 	return true;
 }
 
-/*
- * On APUs with >= 64GB white flickering has been observed w/ SG enabled.
- * Disable S/G on such systems until we have a proper fix.
- * https://gitlab.freedesktop.org/drm/amd/-/issues/2354
- * https://gitlab.freedesktop.org/drm/amd/-/issues/2735
- */
-bool amdgpu_sg_display_supported(struct amdgpu_device *adev)
-{
-	switch (amdgpu_sg_display) {
-	case -1:
-		break;
-	case 0:
-		return false;
-	case 1:
-		return true;
-	default:
-		return false;
-	}
-	if ((totalram_pages() << (PAGE_SHIFT - 10)) +
-	    (adev->gmc.real_vram_size / 1024) >= 64000000) {
-		DRM_WARN("Disabling S/G due to >=64GB RAM\n");
-		return false;
-	}
-	return true;
-}
-
 /*
  * Intel hosts such as Raptor Lake and Sapphire Rapids don't support dynamic
  * speed switching. Until we have confirmation from Intel that a specific host
diff --git a/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index d1f1c5f79dc..572c3c83e37 100644
--- a/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1636,8 +1636,9 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
 		}
 		break;
 	}
-	if (init_data.flags.gpu_vm_support)
-		init_data.flags.gpu_vm_support = amdgpu_sg_display_supported(adev);
+	if (init_data.flags.gpu_vm_support &&
+	    (amdgpu_sg_display == 0))
+		init_data.flags.gpu_vm_support = false;
 
 	if (init_data.flags.gpu_vm_support)
 		adev->mode_info.gpu_vm_support = true;