________________________________ Hi,
I am trying to get QMAPv5 working on a Quectel RM520N modem with rmnet. It works when used with Quectels qmi_wwan_q but we use the mainline driver and with it I am not able to get it to work. I am setting the following as data format, this is what I reverse engineered from QMI calls that Quectels CM does when used on their driver and it works rather well with it: qmicli -p -d /dev/cdc-wdm0 --wda-set-data-format="link-layer-protocol=raw-ip,ul-protocol=qmapv5,dl-protocol=qmapv5,dl-max-datagrams=62,dl-datagram-max-size=31744,ep-type=hsusb,ep-iface-number=4,ul-datagram-max-size=8192,ul-max-datagrams=11" Previously I have created an rmnet interface on top of wwan0 which is the default qmi_wwan interface with the mux_id of 129 and then: qmicli -p -d /dev/cdc-wdm0 --client-no-release-cid --wds-noop qmicli -p -d /dev/cdc-wdm0 --client-cid=15 --client-no-release-cid --wds-bind-mux-data-port="mux-id=129,ep-type=hsusb,ep-iface-number=4" qmicli -p -d /dev/cdc-wdm0 --client-cid=15 --client-no-release-cid --wds-start-network="apn=internet.ht.hr,ip-type=4" Modem connects to the network and starts the data connection which I can see with --wds-get-current-settings just fine but after bringing up the rmnet interface I just cannot get any traffic on it. I have tried searching around and I found the limitations of qmi-wwan rx_urb_size being tied to MTU of the interface which posed an issue with rmnet limiting its MTU to 16k. I have tried changing that limit to 32k and changing the MTU, or adding the rejected qmi_wwan rx_urb_size sysfs entry but even with those I cannot get any traffic to pass. The only combination in which QMAPv5 works with qmi_wwan is when I used ModemManager to create a multiplexed bearer but I get reduced performance compared to without multiplexing with that combination. The deprecated syfs based muxing QMAPv1 works with the modem but performance is again lower than without multiplexing. Basically, I am trying to get QMAPv5 working so packets are aggregated as on the device we use kernel 5.4 (I know, I dont like it either) and qmi_wwan is rather slow on it currently and hogging the CPU. Using mainline OpenWrt with kernel 6.6 provides much better performance but even after backporting all qmi_wwan changes that are bugfixes I just cannot get anywhere near that performance on 5.4. But on the other hand Quectels qmi_wwan_q driver works great, it has much lower CPU load and I am able to get over 1Gbps when using loopback testing via it. I know this has been a bit long mail, but I have kind of hit the wall trying to get some reasonable performance but still using libqmi and ModemManager instead of the crazy qmi_wwan_q and Quectels CM. So if anybody has some pointers or instructions I would be really grateful. Regards, Robert -- Robert Marko Staff Embedded Linux Engineer Sartura d.d. Lendavska ulica 16a 10000 Zagreb, Croatia Email: robert.ma...@sartura.hr Web: www.sartura.hr
