https://bugzilla.kernel.org/show_bug.cgi?id=213839 --- Comment #11 from Jonathan McDowell (noodles@xxxxxxxx) --- Autosuspend appears to be the issue; if I disable it using the echo command provided then the additional ports on the hub work ok and the flash drive is detected. Looking at my kernel config (this is Debian 11/bullseye, their stock 5.10.70-1 kernel) I see: CONFIG_USB_AUTOSUSPEND_DELAY=2 Which according to drivers/usb/core/Kconfig is the default. However hub_probe in drivers/usb/core/hub.c forces the suspend delay for a hub to 0ms as long as autosuspend is enabled. As an experiment, theorising if the first hub chip didn't get put immediately to sleep devices off the 2nd hub chip would be seen, I tried plugging in the hub, plugging a flash drive into a port on the first chip (which is seen, as expected) and then plugging a flash drive into a port on the second chip (which would normally not be seen). Both drives are correctly detected. I'll attach all 3 dmesgs now but it seems like the 0 delay in hub.c is what's causing the problem. -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.
