Closed
Description
Original post here: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=192987
TL;DR:
- I'm seeing sporadic data loss from a Full-Speed USB-to-UART bridge from Silabs (CP2104x) running at 2.000.000 bps (actual data traffic around 1.200.000bps)
- Current settings (tweaking them does not make any difference though):
dwc_otg.nak_holdoff=2 dwc_otg.fiq_enable=1 dwc_otg.fiq_fsm_enable=1 dwc_otg.fiq_fsm_mask=0x7 dwc_otg.speed=1
- First drops occur after about 10-30 minutes
- Identified as a regression between 4.4 and 4.9
- Tested as working with:
- 4.4.38, 4.4.50 (from pre-compiled release)
- 4.8.16 (from source commit 061dccc)
- Tested as broken with:
I'm willing to investigate this further and provide any required input, but I can't really bisect the whole tree.
Please give me some guidance as to where to look and how I could reproduce the issue quicker.
Thank you!