Em Tue, 08 Sep 2020 09:09:46 +0300 Felipe Balbi <balbi@xxxxxxxxxx> escreveu: > >> Why does it affect only Hikey kirin? > > > > As John Stultz didn't re-submit this one (and looking at the DT > > between Kirin 960 and 970 from the original Kernel 4.9 official > > drivers), I suspect that only Kirin 970 requires this quirk. > > > > It could well be due to some Dwc3 revision, but it could also be due > > to some differences at the USB part of the SoC, as there are a > > the reason I ask is that if it's caused by dwc3 revision, then we don't > need the extra dt property, we can rely on a revision check. If it's > something that can't be detected in runtime, then we need a property. Yeah, if it would be possible to auto-detect, that would be better. Yet, hard to say if it would be possible to do that, without access to the Dwc3 docs, and without different hardware for testing it. > > few other things different between hikey 960 and 970: it has a > > different PHY driver, and there are also some differences at the > > USB HUB which is connected into it. > > > > On both devices, the USB physical ports are actually connected > > into a HUB. In the case of Hikey 970, the hub seems to be a > > TI TUSB8041 4-Port Hub: > > > > $ lsusb > > Bus 002 Device 002: ID 0451:8140 Texas Instruments, Inc. TUSB8041 4-Port Hub > > Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub > > Bus 001 Device 004: ID 090c:1000 Silicon Motion, Inc. - Taiwan (formerly Feiya Technology Corp.) Flash Drive > > Bus 001 Device 003: ID 413c:301a Dell Computer Corp. Dell MS116 Optical Mouse > > Bus 001 Device 002: ID 0451:8142 Texas Instruments, Inc. TUSB8041 4-Port Hub > > Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub > > > >> What's the dwc3 revision on > >> that SoC (grep SNPSID /sys/kernel/debugfs/*dwc3/regdump)? > > > > GSNPSID = 0x33313130 > > This isn't even listed as a known revision in dwc3/core.h. Thinh, could > the issue being described here caused by a known Erratum with this > particular revision? Maybe. Again, hard to tell without any documentation from Synopsys. Maybe some of the Synopsys folks at USB MK can shed a light. Thanks, Mauro
