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 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: USB Assignee: drivers_usb@xxxxxxxxxxxxxxxxxxxxxx Reporter: slark_xiao@xxxxxxx Regression: No 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. This issue can not reproduced with MBIM port. Also, Windows can't reproduce the RMNET issue. -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.
