[PATCH 4/6] drm_hyperv: Remove support for synth video protocol of old Hyper-V hosts

[Michael Kelley]

From: Michael Kelley <mhklinux@xxxxxxxxxxx>

With the overall removal of Linux support for running on Hyper-V
hosts earlier than WS2016 and Windows 10, it's no longer necessary
to support older synthetic video protocols. Remove the support.

Signed-off-by: Michael Kelley <mhklinux@xxxxxxxxxxx>
---
 drivers/gpu/drm/hyperv/hyperv_drm_proto.c | 33 +++++++----------------
 1 file changed, 10 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/hyperv/hyperv_drm_proto.c b/drivers/gpu/drm/hyperv/hyperv_drm_proto.c
index f0ef627b4898..cea1ea2595cd 100644
--- a/drivers/gpu/drm/hyperv/hyperv_drm_proto.c
+++ b/drivers/gpu/drm/hyperv/hyperv_drm_proto.c
@@ -17,7 +17,7 @@
 #define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
 #define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)
 
-/* Support for VERSION_WIN7 is removed. #define is retained for reference. */
+/* Support for WIN7 and WIN8 is removed. #define's retained for reference. */
 #define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
 #define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
 #define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)
@@ -557,23 +557,12 @@ int hv_drm_connect_vsp(struct hv_device *hdev)
 		return ret;
 	}
 
-	/* Negotiate the protocol version with host */
-	switch (vmbus_proto_version) {
-	case VERSION_WIN10:
-	case VERSION_WIN10_V5:
-		ret = hv_drm_negotiate_version(hdev, SYNTHVID_VERSION_WIN10);
-		if (!ret)
-			break;
-		fallthrough;
-	case VERSION_WIN8:
-	case VERSION_WIN8_1:
-		ret = hv_drm_negotiate_version(hdev, SYNTHVID_VERSION_WIN8);
-		break;
-	default:
-		ret = hv_drm_negotiate_version(hdev, SYNTHVID_VERSION_WIN10);
-		break;
-	}
-
+	/*
+	 * Negotiate the protocol version with host. Since support for hosts
+	 * older than WIN10 has been removed from Linux, only negotiate the
+	 * WIN10 version.
+	 */
+	ret = hv_drm_negotiate_version(hdev, SYNTHVID_VERSION_WIN10);
 	if (ret) {
 		drm_err(dev, "Synthetic video device version not accepted %d\n", ret);
 		goto error;
@@ -581,11 +570,9 @@ int hv_drm_connect_vsp(struct hv_device *hdev)
 
 	hv->screen_depth = SYNTHVID_DEPTH_WIN8;
 
-	if (hv_drm_version_ge(hv->synthvid_version, SYNTHVID_VERSION_WIN10)) {
-		ret = hv_drm_get_supported_resolution(hdev);
-		if (ret)
-			drm_err(dev, "Failed to get supported resolution from host, use default\n");
-	}
+	ret = hv_drm_get_supported_resolution(hdev);
+	if (ret)
+		drm_err(dev, "Failed to get supported resolution from host, use default\n");
 
 	if (!hv->screen_width_max) {
 		hv->screen_width_max = SYNTHVID_WIDTH_WIN8;
-- 
2.25.1