On Sun, Nov 22, 2015 at 11:47:17AM +0100, Jonas Jonsson wrote: > Some modems, such as the Telit UE910, are using an Infineon Flash Loader > utility. It has two interfaces, 2/2/0 (Abstract Modem) and 10/0/0 (CDC > Data). The latter can be used as a serial interface to upgrade the > firmware of the modem. However, that isn't possible when the cdc-acm > driver takes control of the device. > > The following is an explanation of the behaviour by Daniele Palmas during > discussion on linux-usb. > > "This is what happens when the device is turned on (without modifying > the drivers): > > [155492.352031] usb 1-3: new high-speed USB device number 27 using ehci-pci > [155492.485429] usb 1-3: config 1 interface 0 altsetting 0 endpoint 0x81 has an invalid bInterval 255, changing to 11 > [155492.485436] usb 1-3: New USB device found, idVendor=058b, idProduct=0041 > [155492.485439] usb 1-3: New USB device strings: Mfr=0, Product=0, SerialNumber=0 > [155492.485952] cdc_acm 1-3:1.0: ttyACM0: USB ACM device > > This is the flashing device that is caught by the cdc-acm driver. Once > the ttyACM appears, the application starts sending a magic string > (simple write on the file descriptor) to keep the device in flashing > mode. If this magic string is not properly received in a certain time > interval, the modem goes on in normal operative mode: > > [155493.748094] usb 1-3: USB disconnect, device number 27 > [155494.916025] usb 1-3: new high-speed USB device number 28 using ehci-pci > [155495.059978] usb 1-3: New USB device found, idVendor=1bc7, idProduct=0021 > [155495.059983] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 > [155495.059986] usb 1-3: Product: 6 CDC-ACM + 1 CDC-ECM > [155495.059989] usb 1-3: Manufacturer: Telit > [155495.059992] usb 1-3: SerialNumber: 359658044004697 > [155495.138958] cdc_acm 1-3:1.0: ttyACM0: USB ACM device > [155495.140832] cdc_acm 1-3:1.2: ttyACM1: USB ACM device > [155495.142827] cdc_acm 1-3:1.4: ttyACM2: USB ACM device > [155495.144462] cdc_acm 1-3:1.6: ttyACM3: USB ACM device > [155495.145967] cdc_acm 1-3:1.8: ttyACM4: USB ACM device > [155495.147588] cdc_acm 1-3:1.10: ttyACM5: USB ACM device > [155495.154322] cdc_ether 1-3:1.12 wwan0: register 'cdc_ether' at usb-0000:00:1a.7-3, Mobile Broadband Network Device, 00:00:11:12:13:14 > > Using the cdc-acm driver, the string, though being sent in the same way > than using the usb-serial-simple driver (I can confirm that the data is > passing properly since I used an hw usb sniffer), does not make the > device to stay in flashing mode." > > Signed-off-by: Jonas Jonsson <jonas@xxxxxxxxxxx> > Tested-by: Daniele Palmas <dnlplm@xxxxxxxxx> Thanks for the update, these both look good to me now. Greg, hope you don't mind if I take also the cdc-acm patch through my tree? Thanks, Johan -- 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
