On 6 July 2018 at 18:57, Doug Anderson <dianders@xxxxxxxxxxxx> wrote: > Hi, > > Thanks for tracking this down and sorry for the original regression. > Seems like a good fix. With this fix, I'd be curious of your > observations on how dwc2 performs (both performance and compatibility > under stress) with the newest driver compared to whatever you were > using before. > My totally not scientifically accurate performance test included running iperf through my LTE dongle that was connected to dwc2. I saw throughput increase in download speeds. Before (kernel 4.9.109 with the offending commit reverted) iperf reported download bandwidth at 33.2 Mbits/sec Using newest dwc2 driver after applying "Fix DMA alignment to start at allocated boundary" patch I got 38.2 Mbits/sec If I also apply the "Fix inefficient copy of unaligned buffers" patch I could achieve a total throughput for download around 44.6 Mbits/sec which I believe is capped by my 50Mbit/s subscription. > Also: you're using the dwc2_set_ltq_params() parameters? Have you > checked if removing the "max_transfer_size" limit boosts your > performance? > Yes, I'm using the parameters set there. I tried removing max_transfer_size but it did not have noticeable impact on the performance in my tests. > Cc: stable@xxxxxxxxxxxxxxx > Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx> Thanks for reviewing :) -Antti
