From: Saurabh Sengar <ssengar@linux.microsoft.com>
Date: Fri, 23 Sep 2022 10:09:50 +0000
Patch-mainline: v6.1-rc1
Subject: drm/hyperv: Don't overwrite dirt_needed value set by host
Git-commit: 19b5e6659eaf537ebeac90ae30c7df0296fe5ab9
References: git-fixes

Existing code is causing a race condition where dirt_needed value is
already set by the host and gets overwritten with default value. Remove
this default setting of dirt_needed, to avoid overwriting the value
received in the channel callback set by vmbus_open. Removing this
setting also means the default value for dirt_needed is changed to false
as it's allocated by kzalloc which is similar to legacy hyperv_fb driver.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1662996766-19304-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Olaf Hering <ohering@suse.de>
---
 drivers/gpu/drm/hyperv/hyperv_drm_drv.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
--- a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
+++ b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
@@ -142,8 +142,6 @@ static int hyperv_vmbus_probe(struct hv_device *hdev,
 	if (ret)
 		drm_warn(dev, "Failed to update vram location.\n");
 
-	hv->dirt_needed = true;
-
 	ret = hyperv_mode_config_init(hv);
 	if (ret)
 		goto err_free_mmio;