Bug 238652 - [USB] Timeout errors on boot with Intel ATOM cpus
Summary: [USB] Timeout errors on boot with Intel ATOM cpus
Status: New
Alias: None
Product: Base System
Classification: Unclassified
Component: usb (show other bugs)
Version: 11.2-RELEASE
Hardware: amd64 Any
: --- Affects Some People
Assignee: freebsd-usb (Nobody)
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-06-17 10:28 UTC by Masse Nicolas
Modified: 2019-06-17 10:28 UTC (History)
0 users

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Description Masse Nicolas 2019-06-17 10:28:35 UTC
When booting a device using an Intel E3845 cpu, we see the following usb errors in the dmesg:
[6] usbus1: port reset timeout
[6] uhub_reattach_port: port 1 reset failed, error=USB_ERR_TIMEOUT
[6] uhub_reattach_port: device problem (USB_ERR_TIMEOUT), disabling port 1

Although we receive those errors, usb ports are working as expexted.
In fact those errors comes from the EHCI driver, but the ports seems to be using the XHCI one.

My guess is that the system try to attach both driver to the same device, since the cpu does expose both interfaces (XHCI should be preferred, EHCI is exposed mainly for compatibility reasons)

In order to check that I tried to force the XHCI mode in the BIOS, and this  made those errors disappears (the problem here being that we can't access the BIOS from our customers), which seems to confirm my supposition.

How do you think we could address the problem?