On Thursday, February 8, 2018 3:43:05 PM EST Greg KH wrote: > On Thu, Feb 08, 2018 at 02:16:08PM +0000, Tomasz Janowski, Ph.D. wrote: > > Dear USB developers, > > > > Based on my google research, the problem I experience seems to happen > > with some newer smartphones. My test case is Samsung Galaxy S8 (SM-950U1). > > I am trying to use USB tethering and everything seems to work as expected > > (modules are loaded, Ethernet devices are up and running, dhcp works > > fine). I can connect to the external world using both LTE or wireless > > network on the phone. > > > > Now, the problem is that the download speeds are terrible, around 64 KB/s, > > while uploads are fast, the order of 15 MB/s. These speeds do not depend > > on the wireless service provider: the results are similar when I tether > > wi-fi. The USB Ethernet interface on the Linux host reports a lot of > > receive errors (attached: device_state.txt), while kernel reports bad > > rndis messages (attached: kernel.log.txt). > > > > Windows 10 works great with the same hardware (same PC and same phone), > > with uploads and downloads in the order of 150 Mbit/s, which is probably > > as fast as my wireless network can do. But some people reported issues > > with older Windows drivers too. Is possible that some newer version of > > RNDIS protocol is around and Linux hasn't updated its RNDIS module yet? > > Hey, I was _just_ talking to someone at Google about this same issue > yesterday, you beat him sending this same type of report to the mailing > list, nice job :) > > Yes, this is not good, and we should work to resolve this, but first, > what kernel version are you using? I think some fixes for the rndis > driver went in recently to 4.15, but it would be good to verify that > this isn't already resolved.
The error messages which I have attached were produced by a precompiled Debian kernel: "Linux version 4.14.0-0.bpo.3-amd64 (debian-ker...@lists.debian.org) (gcc version 6.3.0 20170516 (Debian 6.3.0-18)) #1 SMP Debian 4.14.13-1~bpo9+1 (2018-01-14)". But I have downloaded the most recent version of the kernel from the official git repository (last commit: Jan 31, 2018) and it had exactly the same problem. Unless a patch was submitted within the last week, the issue is still there. Should I get the version as of today and test it again? Thanks! Tomasz