From: Michael Kelley <mikelley@microsoft.com>

Date: Tue, 20 Apr 2021 08:44:19 -0700

Patch-mainline: v5.13-rc1

Subject: video: hyperv_fb: Add ratelimit on error message

Git-commit: aa5b7d11c7cb87c266d705b237368985e7171958

References: bsc#1185724

Due to a full ring buffer, the driver may be unable to send updates to

the Hyper-V host.  But outputing the error message can make the problem

worse because console output is also typically written to the frame

buffer.  As a result, in some circumstances the error message is output

continuously.

Break the cycle by rate limiting the error message.  Also output

the error code for additional diagnosability.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>

Link: https://lore.kernel.org/r/1618933459-10585-1-git-send-email-mikelley@microsoft.com

Signed-off-by: Wei Liu <wei.liu@kernel.org>

Acked-by: Olaf Hering <ohering@suse.de>

---

 drivers/video/fbdev/hyperv_fb.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c

--- a/drivers/video/fbdev/hyperv_fb.c

+++ b/drivers/video/fbdev/hyperv_fb.c

@@ -308,7 +308,7 @@ static inline int synthvid_send(struct hv_device *hdev,

 			       VM_PKT_DATA_INBAND, 0);

 	if (ret)

-		pr_err("Unable to send packet via vmbus\n");

+		pr_err_ratelimited("Unable to send packet via vmbus; error %d\n", ret);

 	return ret;

 }