From: Joe Perches <joe@xxxxxxxxxxx> Sent: Tuesday, April 20, 2021 12:59 PM > > On Tue, 2021-04-20 at 08:44 -0700, Michael Kelley wrote: > > 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@xxxxxxxxxxxxx> > > None of the callers of this function ever check the return status. > Why is important/useful to emit this message at all? > Except during device initialization, the messages tell Hyper-V about updates to the frame buffer contents. The fbdev framework functions (such as fillrect) that eventually call synthvid_send() are void functions. So the message is the only alert that something has gone wrong in the communication with Hyper-V, which makes it useful for diagnostic purposes. Michael > > --- > > 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, > > 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; > > } > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel