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 <[email protected]>
---
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
index 4a8941fa0815..57d49a08b37f 100644
--- a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
+++ b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
@@ -198,8 +198,6 @@ 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_vmbus_close;
--
2.31.1
> From: Saurabh Sengar <[email protected]>
> Sent: Monday, September 12, 2022 8:33 AM
> ...
> 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 <[email protected]>
Reviewed-by: Dexuan Cui <[email protected]>
From: Saurabh Sengar <[email protected]> Sent: Monday, September 12, 2022 8:33 AM
>
> 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 <[email protected]>
> ---
> 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
> index 4a8941fa0815..57d49a08b37f 100644
> --- a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> +++ b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> @@ -198,8 +198,6 @@ 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_vmbus_close;
> --
> 2.31.1
Reviewed-by: Michael Kelley <[email protected]>
On Mon, Sep 12, 2022 at 08:32:46AM -0700, Saurabh Sengar wrote:
> 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 <[email protected]>
Applied to hyperv-next. Thanks.
I ended up reconstructing the patch myself since the said driver
changed. It is only a one line change so that's fine. If the committed
patch is wrong, please let me know.