[PATCH 1/1] video: hyperv_fb: Add ratelimit on error message

From: Michael Kelley
Date: Tue Apr 20 2021 - 11:44:59 EST

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

Break the cycle by rate limiting the error message. Also output
the error code for additional diagnosability.

Signed-off-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
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
index 4dc9077..a7e6eea 100644
--- 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,

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;