Hi Bjørn, 2016-11-15 19:56 GMT+01:00 Bjørn Mork <bjorn@xxxxxxx>: > Daniele Palmas <dnlplm@xxxxxxxxx> writes: > >> The problem is in cdc_ncm, function cdc_ncm_bind_common, line >> >> usleep_range(10000, 20000); >> >> It seems that LE922 needs an higher timeout; changing the line to >> >> usleep_range(70000, 80000); >> >> makes the modem to work fine. > > Extremely interesting! As you probably noticed, that delay was recently > added as a workaround for the same problem on Sierra Wireless EM7455 > modems. I believe these are based on the Qualcomm MDM9230. Which > chipset is the LE922 based on? Is it also one of the newer Qualcom > chips? Yes, it is based on one of latest QC chipsets. > > >> I will submit a patch for this. > > Thanks. It would also be great if you could trigger some investigation > into the actual firmware issue. It looks like the firmware returns > control to the driver before it's actually ready at this point of > initialisation. > Yeah, for sure I will ask for some investigation also on the firmware side, even though I don't have many expectations for this. It seems that, if the modem is attached to the host and then turned on, the previous delay is not enough. And then there seems also to be constraints on the application side (e.g. ModemManager). Currently I'm not going to submit a patch until things are more clear. Thanks for your help, Daniele > > > > 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
