Aleksander Morgado <aleksander@xxxxxxxxxxxxx> writes: > On Tue, Jun 26, 2018 at 8:09 AM, Johan Hovold <johan@xxxxxxxxxx> wrote: >> On Sat, Jun 23, 2018 at 11:24:08PM +0200, Aleksander Morgado wrote: >>> This module exposes two USB configurations: a QMI+AT capable setup on >>> USB config #1 and a MBIM capable setup on USB config #2. >>> >>> By default the kernel will choose the MBIM capable configuration as >>> long as the cdc_mbim driver is available. This patch adds support for >>> the serial ports in the secondary configuration. >> >> Could you please post the usb-devices output for this device? >> >> Depending on another driver to select a specific configuration seems >> fragile (and that behaviour is even configurable). >> > > This would be when running on configuration #1: > > T: Bus=04 Lev=03 Prnt=04 Port=02 Cnt=01 Dev#= 7 Spd=5000 MxCh= 0 > D: Ver= 3.10 Cls=ef(misc ) Sub=02 Prot=01 MxPS= 9 #Cfgs= 2 > P: Vendor=413c ProdID=81d7 Rev=03.18 > S: Manufacturer=DELL > S: Product=DW5821e Snapdragon X20 LTE > S: SerialNumber=0123456789ABCDEF > C: #Ifs= 5 Cfg#= 1 Atr=a0 MxPwr=896mA > I: If#=0x0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=qcserial > I: If#=0x1 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=qmi_wwan > I: If#=0x2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=qcserial > I: If#=0x3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=qcserial > I: If#=0x4 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none) > > This would be when running on configuration #2: > > T: Bus=04 Lev=03 Prnt=04 Port=02 Cnt=01 Dev#= 6 Spd=5000 MxCh= 0 > D: Ver= 3.10 Cls=ef(misc ) Sub=02 Prot=01 MxPS= 9 #Cfgs= 2 > P: Vendor=413c ProdID=81d7 Rev=03.18 > S: Manufacturer=DELL > S: Product=DW5821e Snapdragon X20 LTE > S: SerialNumber=0123456789ABCDEF > C: #Ifs= 3 Cfg#= 2 Atr=a0 MxPwr=896mA > I: If#=0x0 Alt= 0 #EPs= 1 Cls=02(commc) Sub=0e Prot=00 Driver=cdc_mbim > I: If#=0x1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=02 Driver=cdc_mbim > I: If#=0x2 Alt= 0 #EPs= 1 Cls=ff(vend.) Sub=ff Prot=ff Driver=qcserial Thanks. This illustrates the arbitrary default configuration choice very well: Imagine switching the order of the qcserial and mbim functions, making qcserial use the first interface. Linux would then select cfg #1 as default, even if the set of functions in both configuratoons were the same as before. Bjørn -- 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
