Hello Bjørn and all, this patchset implements and document tx qmap packets aggregation in qmi_wwan. Low-cat Thread-x based modem are not capable of properly reaching the maximum allowed throughput both in tx and rx during a bidirectional test if tx packets aggregation is not enabled. I verified this problem by using a MDM9207 Cat. 4 based modem (50Mbps/150Mbps max throughput). What is actually happening is pictured at https://drive.google.com/file/d/1xuAuDBfBEIM3Cdg2zHYQJ5tdk-JkfQn7/view?usp=sharing When rx and tx flows are tested singularly there's no issue in tx and minor issues in rx (a few spikes). When there are concurrent tx and rx flows, tx throughput has an huge drop. rx a minor one, but still present. The same scenario with tx aggregation enabled is pictured at https://drive.google.com/file/d/1Kw8TVFLVgr31o841fRu4fuMX9DNZqJB5/view?usp=sharing showing a regular graph. This issue does not happen with high-cat modems (e.g. SDX20), or at least it does not happen at the throughputs I'm able to test currently: maybe the same could happen when moving close to the maximum rates supported by those modems. Anyway, having the tx aggregation enabled should not hurt. It is interesting to note that, for what I can understand, rmnet too does not support tx aggregation. I'm aware that rmnet should be the preferred way for qmap, but I think there's still value in adding this feature to qmi_wwan qmap implementation since there are in the field many users of that. Moreover, having this in mainline could simplify backporting for those who are using qmi_wwan qmap feature but are stuck with old kernel versions. I'm also aware of the fact that sysfs files for configuration are not the preferred way, but it would feel odd changing the way for configuring the driver just for this feature, having it different from the previous knobs. Thanks, Daniele Daniele Palmas (2): net: usb: qmi_wwan: implement qmap uplink tx aggregation Documentation: ABI: sysfs-class-net-qmi: document tx aggregation files Documentation/ABI/testing/sysfs-class-net-qmi | 28 ++ drivers/net/usb/qmi_wwan.c | 242 +++++++++++++++++- 2 files changed, 266 insertions(+), 4 deletions(-) -- 2.37.1
