Re: About the reboot hang issue with EHCI driver on the Baytrail platform

From: Alan Stern
Date: Wed Aug 27 2014 - 10:38:18 EST

On Wed, 27 Aug 2014, Gavin Guo wrote:

> > Still, why not use the BIOS setting to disable EHCI?
> It's hardware enablement policy. By default, we can't change the BIOS
> setting to make the bug disappear until we find out the bug is due to
> BIOS's bug. Add kernel parameters is the temporary solution for the
> platform can ship. And if the bug is from kernel, we need to send
> patches to upstream and pull back to Ubuntu kernel or send to Ubuntu
> Kernel directly if it's a trivial solution like adding device id.
> However, as you said, in this case about the bug the root may be from
> BIOS code. So, we can coordinate with the OEM BIOS team to modify the
> default BIOS setting.

There is no doubt that the BIOS is buggy. Your log contains this line:

[ 2.804205] pci 0000:00:1d.0: EHCI: BIOS handoff failed (BIOS bug?) 01010001

The only way that can happen is if the BIOS isn't working right.
However, this may be a different bug from the crashes you've been

Alan Stern

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at