On 15/02/12 01:14, Alexey Orishko wrote:
I have a few Ellisys traces for multifunctional devices connected to
Ubuntu/Intel and
embedded Linux host/MIPS. AltSet=1 for NCM data interface was set in approx.
110-130 ms after SetAddress. Both notifications are received within 400 ms after
SetInterface(AltSet=1), which falls in "a few seconds" period stated above.
I assume that the Ubuntu system had the network-manager daemon running?
If so then the network-manager daemon will be bringing the usb*
interface up almost as soon as it's notified of it existing.
I assume that the MIPS embedded Linux host system had a user-space tool
running similar functionality such as a udevd rule which runs a dhcp
client on the interface when it appears. Was this the case?
If the interface was still down in both of these situations then I must
have misunderstood when the dev->interrupt URB is submitted, and
therefore when usbnet_open is called.
However, if you have 3G modem, it will take 1-2 minutes before user space
application can setup a data call and driver get these notifications.
Makes sense, however the device I'm using doesn't appear to be using the
NCM connection for access to the device modem. The device appears to
only ever send one NetworkConnection notification and it only sends it
if the host is trying to read from the interrupt endpoint in the first
few seconds of setting the interface to altsetting 1. I've confirmed
this using LeCroy USB traces.
The way I'm currently working around this issue is to add a cdc_ncm_reset to
the cdc_ncm_info and moving the setting of the data interface alternate
setting (and related code) from cdc_ncm_bind to cdc_ncm_reset. Does this
seem the sensible solution?
NCM driver doesn't read notifications directly, but via callback from
intr_complete.
Initialization is done in usbnet right after bind call, so I'm not
sure that proposed
change solves the real problem.
It's true that the dev->interrupt URB is created by usbnet after the
bind call, but my understanding was it was only submitted (and therefore
you only start to see IN tokens on the USB bus) when usbnet_open was called?
I'm going to post the patch series to the mailing list as it will
hopefully better explain what I'm trying to achieve.
Regards,
Toby
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