>>>> Hey all, >>>> I wanted to send these out for comment and thoughts. >>>> >>>> Since ~4.20, when the functionfs gadget enabled scatter-gather >>>> support, we have seen problems with adb connections stalling and >>>> stopping to function on hardware with dwc3 usb controllers. >>>> Specifically, HiKey960, Dragonboard 845c, and Pixel3 devices. >>> >>> Any chance this: >>> >>> https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git/commit/ >>> ?h=testing/next&id=f63333e8e4fd63d8d8ae83b89d2c38cf21d64801 >> This is a different issue. I have tried initializing num_sgs when debugging this adb stall problem, but it didn't help. > > So multiple folks have run through this problem, but not *one* has tracepoints collected from the issue? C'mon guys. Can someone, please, collect tracepoints so we can figure out what's actually going on? > > I'm pretty sure this should be solved at the DMA API level, just want to confirm. I have sent you the tracepoints long time ago. Also my analysis of the problem (BTW, I don't think the tracepoints helped much). It's basically a logic problem in function dwc3_gadget_ep_reclaim_trb_sg(). I can try dig into my old emails and resend, but that is a bit hard to find. -Fei
