On Tue, Feb 14, 2012 at 12:18 PM, Toby Gray <toby.gray@xxxxxxxxxxx> wrote: > I've been looking into an issue with network interfaces failing to come up > on a particular NCM device, a Nokia 701 mobile phone. The issue is that the > phone does not send the ConnectionSpeedChange and NetworkConnection > notifications (NCM specification section 6.3) if the host isn't trying to > read from the control interrupt endpoint in the first few seconds after the > data interface alternate setting is selected. 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. 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. > 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. Regards, Alexey -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
