Event ring full using qmi_wwan but not cdc_mbim

[Nick B]

Good day,

I have noticed that when using qmi_wwan when I run a speed test I will start to see a fair amount (more than ten per test) of these...
[  643.225139] xhci-hcd xhci-hcd.0.auto: ERROR unknown event type 37

I have searched around and found that it is probably an "even ring full” error generated by the xhci module.
But I do not see this error when running the same test while running the cdc_mbim driver.  Just curious if anyone knows why that might be?

I’m on OpenWrt and have seen the same behaviour on two boards with two modems, MC7430 with MT7621-based board (about a year ago with then-current MM and friends) and more recently with an EM7565 on an IPQ4019-based board.


Best,
Nick B