Re: [Qemu-devel] [PATCH 1.3] ehci-sysbus: Attach DMA context.

[walimis]

On Mon, Dec 03, 2012 at 01:51:00PM +0100, Gerd Hoffmann wrote:
>  Hi,
>
>> As said in another mail, I found that the root cause is that xilinx_zynq has
>> two EHCI controller. If we use usb-storage disk, the disk will be attached to
>> the second EHCI controller, which the kernel uses the first EHCI controller
>> by default.
>
>For the linux kernel it shouldn't matter where the usb stick is
>connected.  Assuming it finds both ehci controllers.  Does it?

The default device tree of linux kernel has only the first ehci controller
support, so the kernel can't detect the second controller. 
But the usb-storage disk is attached to the second controller, so that 
the disk is failed to be detected by the linux kernel.


>
>> For now, qemu doesn't support two EHCI controller, could we remove the second
>> EHCI from xilinx_zynq?
>
>Two controllers should work just fine.  I'd suggest to find the root

Yes, they work fine separately, but I don't know how to use them at the
same time (I mean both controller have device attached) as I have
mentioned in the another mail.

Liming Wang

>cause instead of doctoring like this.  ehci + usb core are fine with two
>controllers & busses, maybe the arch plumbing (device tree?) misses
>something so the linux kernel doesn't find the second ehci controller.
>
>cheers,
>  Gerd
>