From: jsg <jsg@openbsd.org>
Date: Thu, 17 Aug 2023 03:41:15 +0000 (+0000)
Subject: drm/amdgpu: add S/G display parameter
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=676a087ae56ba73bd7bad2f2ee67fcb49d057454;p=openbsd

drm/amdgpu: add S/G display parameter

From Alex Deucher
f6166ca452b8687322e6c1f8bac2395abc456aa4 in linux-6.1.y/6.1.46
bf0207e1727031798f300afa17f9bbeceac6da87 in mainline linux
---

diff --git a/sys/dev/pci/drm/amd/amdgpu/amdgpu.h b/sys/dev/pci/drm/amd/amdgpu/amdgpu.h
index cfad9d3fd3f..7bac1c1336f 100644
--- a/sys/dev/pci/drm/amd/amdgpu/amdgpu.h
+++ b/sys/dev/pci/drm/amd/amdgpu/amdgpu.h
@@ -246,6 +246,7 @@ extern int amdgpu_num_kcq;
 
 #define AMDGPU_VCNFW_LOG_SIZE (32 * 1024)
 extern int amdgpu_vcnfw_log;
+extern int amdgpu_sg_display;
 
 #define AMDGPU_VM_MAX_NUM_CTX			4096
 #define AMDGPU_SG_THRESHOLD			(256*1024*1024)
diff --git a/sys/dev/pci/drm/amd/amdgpu/amdgpu_drv.c b/sys/dev/pci/drm/amd/amdgpu/amdgpu_drv.c
index 630ba2f33aa..1e2c32dd8e2 100644
--- a/sys/dev/pci/drm/amd/amdgpu/amdgpu_drv.c
+++ b/sys/dev/pci/drm/amd/amdgpu/amdgpu_drv.c
@@ -185,6 +185,7 @@ int amdgpu_num_kcq = -1;
 int amdgpu_smartshift_bias;
 int amdgpu_use_xgmi_p2p = 1;
 int amdgpu_vcnfw_log;
+int amdgpu_sg_display = -1; /* auto */
 
 static void amdgpu_drv_delayed_reset_work_handler(struct work_struct *work);
 
@@ -929,6 +930,16 @@ module_param_named(num_kcq, amdgpu_num_kcq, int, 0444);
 MODULE_PARM_DESC(vcnfw_log, "Enable vcnfw log(0 = disable (default value), 1 = enable)");
 module_param_named(vcnfw_log, amdgpu_vcnfw_log, int, 0444);
 
+/**
+ * DOC: sg_display (int)
+ * Disable S/G (scatter/gather) display (i.e., display from system memory).
+ * This option is only relevant on APUs.  Set this option to 0 to disable
+ * S/G display if you experience flickering or other issues under memory
+ * pressure and report the issue.
+ */
+MODULE_PARM_DESC(sg_display, "S/G Display (-1 = auto (default), 0 = disable)");
+module_param_named(sg_display, amdgpu_sg_display, int, 0444);
+
 /**
  * DOC: smu_pptable_id (int)
  * Used to override pptable id. id = 0 use VBIOS pptable.
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 2eefe97aff7..d9e78102880 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
@@ -1636,6 +1636,9 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
 		}
 		break;
 	}
+	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;