Hi Alan,
2005/12/15, Alan Stern <[EMAIL PROTECTED]>:
>
> No, the bus should already be suspended. In fact, you should fail the
> driver-suspend request if the bus isn't already suspended.
hmm I think so but I don't see this behaviour in isp116 or sl811 hcds.
The former do actually nothing, even if the bus is not suspended, the
later does a bus_suspend which does nothing. Actually it's hard from
that point to do something usefull since to suspend the bus we need to
suspend all devices connected on it.
> Likewise, you
> should fail a bus-resume request if the driver is suspended.
>
How could it happen ??
> No, you're confused. The root hub _does_ need to support that request,
> because that's how you suspend a device plugged into the root hub. To
> "suspend" the root hub itself, you would need to send this request to the
> root hub's "parent" -- which doesn't exist.
>
> On the other hand, the root hub _is_ allowed to ignore the
> DEVICE_REMOTE_WAKEUP feature. It never gets sent to the root hub; instead
> remote wakeup is assumed to be enabled and can be disabled through sysfs.
>
OK, I think I get the main idea of suspend/resume process for usb. But
now, I don't see the purpose of hcd->bus_suspend method. What is it
supposed to do since all of its children must be suspended (meaning
that the bus is already suspended) before executing this method ? I
guess I don't see the purpose since I have a host controller with only
one port, no root hub.
BTW, I notice a regression. I can not use anymore my usb stick with an
embedded hub, I got the following error message:
"""
usb 1-1: new full speed USB device using vusb-hcd and address 5
usb 1-1: can't connect bus-powered hub to this port
hub 1-0:1.0: state 5 ports 1 chg 0000 evt 0002
"""
Here is the device description:
T: Bus=01 Lev=02 Prnt=06 Port=01 Cnt=01 Dev#= 7 Spd=12 MxCh= 1
D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=067b ProdID=2515 Rev= 1.00
S: Manufacturer=Prolific Technology Inc.
S: Product=USB Embedded Hub
C:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr=100mA
I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
E: Ad=81(I) Atr=03(Int.) MxPS= 1 Ivl=12ms
T: Bus=01 Lev=03 Prnt=07 Port=00 Cnt=01 Dev#= 8 Spd=12 MxCh= 0
D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=067b ProdID=2517 Rev= 1.00
S: Manufacturer=Prolific Technology Inc.
S: Product=USB Mass Storage Device
C:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr= 2mA
I: If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=05 Prot=50 Driver=usb-storage
E: Ad=01(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms
E: Ad=82(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms
Thanks
--
Franck
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