On Tue, 29 Jul 2014, Michael Welling wrote: > Today I enabled debugging in the core hub driver and found that > once the external HUB suspends, the root HUB suspends. Naturally. You can prevent that by forcing the root hub to remain active. > Once the root HUB suspends, it seems there is no way for the external > HUB to wake the root HUB with the hardware setup that I have. > Here is what happens when I echo on into the power control for the HUB > afterwards: > > root@som3517:/# echo on > /sys/bus/usb/devices/1-1/power/control > [ 1050.003689] hub 1-0:1.0: hub_resume > [ 1050.011306] usb usb1-port1: status 0507 change 0000 > [ 1050.019975] hub 1-0:1.0: state 7 ports 3 chg 0000 evt 0000 > [ 1050.028076] usb 1-1: usb auto-resume > [ 1050.065904] hub 1-0:1.0: state 7 ports 3 chg 0000 evt 0002 > [ 1050.084623] usb 1-1: finish resume > [ 1050.092469] usb 1-1: retry with reset-resume > [ 1050.156167] hub 1-0:1.0: port_wait_reset: err = -16 > [ 1050.161331] usb usb1-port1: not enabled, trying reset again... > [ 1050.376402] usb usb1-port1: logical disconnect > [ 1050.381354] usb 1-1: gone after usb resume? status -19 > [ 1050.386941] usb 1-1: can't resume, status -19 > [ 1050.391537] usb usb1-port1: logical disconnect > [ 1050.400203] usb usb1-port1: status 0100, change 0003, 12 Mb/s > [ 1050.406410] usb 1-1: USB disconnect, device number 2 > [ 1050.411650] usb 1-1: unregistering device > [ 1050.604563] usb usb1-port1: debounce total 100ms stable 100ms status 0x100 > [ 1050.611901] hub 1-0:1.0: state 7 ports 3 chg 0000 evt 0000 > [ 1050.618428] hub 1-0:1.0: hub_suspend The hub disconnects. > Further research led me to find multiple errata that may be causing this > issue. > > www.ti.com/lit/pdf/sprz306 That 1.1.18 advisory looks pretty bad. > Still does not explain why the same hardware works with the 2.6.37 and > 3.2 kernels. Maybe you should try bisection. It's slow but it gives you an answer. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
