On Monday 26 November 2012 10:42:48 Daniele Palmas wrote: > Hello, > > I'm using the modem Telit HE910 with cdc-acm driver. > > I've found that after a suspend and resume of the operating system > (e.g. pm-suspend), the modem does not answer anymore. > > Collecting logs with an usb sniffer, it seems that, unlike the Windows > driver, the host does not send the packet SET_FEATURE DEVICE_REMOTE > WAKEUP, needed by the modem. This is a new quirk. > I've added few lines of code (in the acm_suspend function) for sending > this packet and now things work. acm_suspend is definitely not the place to put this, even if it fixes your particular usage. > According to the USB 2.0 specs it seems to me that this feature should > be always requested when suspending a device, so probably the driver > behavior is not correct. Hm. Which part of the spec do you base this on? > Does cdc-acm really not support this feature or am I missing some > configuration parameters that enable the sending of this request? For a modem this feature makes relatively little sense. I've never seen a modem that doesn't hang up when you suspend it. Regards Oliver -- 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
