On Mon, Jan 10, 2022 at 11:23:13AM +0000, bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=215475 > > Bug ID: 215475 > Summary: RMNET data connection speed would be reduced to about > 80-100Mb/s from 150Mb/s if try to re-connect it > Product: Drivers > Version: 2.5 > Kernel Version: 5.13.0 Does this also happen on 5.16? > Created attachment 300251 > --> https://bugzilla.kernel.org/attachment.cgi?id=300251&action=edit > iperf test result > > We have a Qualcomm modem device which support MBIM and RMNET over USB. > For RMNET, the download-link speed would be reduced to 80 Mb/s if re-connect > it once. The expected speed should be 150 Mb/s. > Test step as below: > 1. Switch device to RMNET USB composition. > 2. Connect it to host PC(kernel 5.13). > 3. Start a data connection with nmcli related settings. > 4. Start a iperf test with simulated network(CMW500). Test result is about > 145 Mb/s ,and protocol is TCP. > 5. Disconnect the connection by turning off the signal, setting AT+CFUN=0， or > deleting the data connection in the host. > 6. Re-connect it again. > 7. The TCP iperf test could only reach to about 80-100Mb/s. If you look at the usb traces, is the data the same? Any long pauses? thanks, greg k-h
