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Re: [Qemu-devel] USB PCI host bus adapter hot plug
From: |
Alexey Kardashevskiy |
Subject: |
Re: [Qemu-devel] USB PCI host bus adapter hot plug |
Date: |
Wed, 13 Aug 2014 16:02:04 +1000 |
User-agent: |
Mozilla/5.0 (X11; Linux i686 on x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0 |
On 08/13/2014 03:00 PM, Gonglei (Arei) wrote:
>>>>> I noticed that QMP's "device_add usb-ehci,id=i2,bus=pci.0" fails on PCI
>>>>> hotplug. The same for pci-ohci and this is because their initfn() do
>>>>> "dc->hotpluggable = false". So I removed those and now I can hotplug
>> USB
>>>>> hosts but none of them is able to actually work:
>>>>>
>>>>> address@hidden:~# echo 1 >/sys/bus/pci/rescan
>>>>> [ 41.143062] ohci-pci 0000:00:01.0: init err (c8700000 0000)
>>>>> [ 41.143133] ohci-pci 0000:00:01.0: can't start
>>>>> [ 41.143227] ohci-pci 0000:00:01.0: startup error -75
>>>>> [ 41.144202] ohci-pci 0000:00:01.0: init 0000:00:01.0 fail, -75
>>>>>
>>>>>
>>>>> address@hidden:~# echo 1 >/sys/bus/pci/rescan
>>>>> [ 43.691067] ehci-pci 0000:00:01.0: can't setup: -110
>>>>> [ 43.692424] ehci-pci 0000:00:01.0: init 0000:00:01.0 fail, -110
>>>>>
>>>>>
>>>>> Why is that? Is QEMU just missing some bits or there is some fundamental
>>>>> issue which I just do not see? Thanks!
>>>>>
>>>> Cc'ing Gerd.
>>>>
>>>> Actually I have post a patch serials for supporting usb host adapter
>> hotplugging,
>>>> Which has been involved in Gerd's (the USB mantainer) usb-next tree. Please
>> see:
>>>> https://www.kraxel.org/cgit/qemu/log/?h=rebase/usb-next
>>>>
>>>> The function of usb host adapter hotplugging is ok. You are welcome to test
>> it.
>>>
>>> It does not work for me though. The device appears in the system but the
>>> driver fails to bring it up:
>>>
>>> address@hidden ~]# echo 1 >/sys/bus/pci/rescan
>>>
>>> [ 43.482378] pci 0000:00:01.0: BAR 0: assigned [mem
>>> 0x100a0000000-0x100a0000fff]
>>> [ 43.488851] ehci-pci 0000:00:01.0: EHCI Host Controller
>>>
>>> [ 43.490153] ehci-pci 0000:00:01.0: new USB bus registered, assigned bus
>>> number 1
>>> [ 43.504957] ehci-pci 0000:00:01.0: can't setup: -110
>>>
>>> [ 43.505028] ehci-pci 0000:00:01.0: USB bus 1 deregistered
>>>
>>> [ 43.507660] ehci-pci 0000:00:01.0: init 0000:00:01.0 fail, -110
>>>
>>> [ 43.507808] ehci-pci: probe of 0000:00:01.0 failed with error -110
>>>
>>>
>>>
>>>> BTW, What's your guest os type?
>>>
>>> Fedora20/ppc64 or Ubuntu14/ppc64le.
>>>
>>> I tried your tree merged with
>>> https://github.com/mdroth/qemu/tree/spapr-pci-hotplug-ppc-next-cleanup2
>>>
>>> I am adding PCIhotplug-on-PPC experts to the thread, may be they have
>> ideas...
>>
>>
>> More precise - this fails:
>>
>> drivers/usb/host/ehci-hcd.c:
>>
>> int ehci_handshake(struct ehci_hcd *ehci, void __iomem *ptr,
>> u32 mask, u32 done, int usec)
>> {
>> u32 result;
>>
>> do {
>> result = ehci_readl(ehci, ptr);
>> if (result == ~(u32)0) /* card removed */
>> return -ENODEV;
>> result &= mask;
>> if (result == done)
>> return 0;
>> udelay (1);
>> usec--;
>> } while (usec > 0);
>> return -ETIMEDOUT; // <------------------
>> }
>>
>> --
>> Alexey
>
> Hi, Alexey.
>
> Does this work when you configure
> EHCI at the command line, not hotplugging?
Yes, all possible USB hosts work just fine when added in the command line.
> BTW, I'm not familiar with PCIhotplug-on-PPC. Sorry for this.
I doubt this is because of PPC but there is always a chance :)
--
Alexey