USB DMA memory Allocation

[Hans Petter Selasky]

On 08/11/13 04:47, aseem.jolly wrote:
> I'm trying to allocate memory from 4GB-8GB range and have modified the memory
> structure(QH,iTD etc) to support 64 bit addressing. I am constantly hitting
> the following issues and I am not sure about the exact meaning of the error
> message(timed out waiting for BIOS).
>
> ehci1: [ITHREAD]
> usbus0: waiting for BIOS to give up control
> usbus0: timed out waiting for BIOS<---Issue 1) ---what does this error
> message mean??
> usbus0: EHCI version 1.0
> usbus0: run timeout<--Issue 2) ---message is coming from ehci_init function,
> EHCI_STS_HCH bit is set in the status register??
> ehci1: USB init failed err=18
>
> Following solution has been posted for issue 1 but I couldn't see such
> option in the BIOS that I am running on.
> http://forums.freebsd.org/showthread.php?t=18783

Hi,

Issue 1) It means that the BIOS did not handover control to the OS of 
the EHCI controller. Possibly you have to turn off USB legacy support in 
the BIOS to get this working.

Issue 2) Run timeout means that the schedule is not correct. Possibly 
you missed some High-DMA pointers.

--HPS