On 20.06.2017 12:47, rocko r wrote:
Whenever I boot my laptop and log into the desktop with a USB-C to USB-3 hub attached and a Samsung 840 EVO SSD attached to the USB-C hub, the laptop locks up completely for kernel versions 4.12-rc1 through 4.12-rc6. Kernels 4.10 and 4.11 do not crash, so this is a regression. The lock-up occurs shortly after logging into the desktop. Note that when I am presented with the lightdm login screen, my mouse attached via the USB-C to USB-3 hub works, but it stops working after the desktop first appears, as if the USB-C hub has gone offline, and then it starts working again maybe five to ten seconds later (this also happens in kernel 4.11, but 4.11 successfully mounts the SSD and does not lock up). Shortly after this in kernels 4.12-rcX, the SSD fails to mount and at some point after this, syslog shows soft lockup errors. Eventually the entire laptop locks up and has to be hard-reset. When I tried 4.12-rc6 today, the laptop locked up almost immediately and did not store a message in syslog. This bug happens every time when rebooting and then logging into the desktop with that particular configuration, ie SSD attached via the USB-C to USB-3 hub. If I have the USB-C to USB-3 hub attached and the SSD attached via one of the laptop's USB-3 ports, the laptop does not lock up. If I plug in the SSD to the USB-C hub after booting into the desktop, the laptop does not lock up. Attached is a log of the soft lockup BUG message from 4.12-rc5 and also another NULL dereference error I noticed today that might be related.
The type-c port is controller by a separate hotpluggable PCI xHCI controller, Looks like that controller disappears for a while, and driver tries to cope with it but hangs while freeing streams. Does the Samsung 840 EVO SSD support UAS (USB attached SCSI?) i.e. does it use the uas driver instead of mass-storage? Could you take full logs from boot with xhci debugging and tracing both enabled? add xhci_hcd.dyndbg=+p or module xhci_hcd +p to kernel cmdline for xhci debugging, and trace_event=xhci-hcd trace_buf_size=10M for tracing Thanks Mathias -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
