[+cc linux-pci, Andreas, switching to email for discussion] On Sat, Sep 13, 2014 at 10:08 AM, <bugzilla-daemon@xxxxxxxxxxxxxxxxxxx> wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=84471 > > Bug ID: 84471 > Summary: pci=assign-busses breaks power-off of T4215 laptop > Product: Drivers > Version: 2.5 > Kernel Version: 3.17.0-rc4 > Hardware: x86-64 > OS: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: PCI > Assignee: drivers_pci@xxxxxxxxxxxxxxxxxxxx > Reporter: thor@xxxxxxxxxxxxxxxxx > Regression: No > > If the kernel argument "pci=assign-busses" is specified as a kernel boot > parameter, power-off does no longer work with the T4215 laptop. The machine > goes through the power-down cycle, but then sits idle with a blank screen after > reporting "powering down". Without the kernel parameter, power-off works > correctly. Thank you very much for the report! It sounds like this is a regression, i.e., power-off used to work correctly with "pci=assign-busses", but it doesn't any more. If that's the case, what's the most recent kernel you know of where it worked correctly? Can you attach complete dmesg and "lspci -vv" output (as root) both with and without "pci=assign-busses" to the bugzilla? If you have an older kernel where power-off works correctly with "pci=assign-busses", please attach the same information for that kernel, too. Why do you use "pci=assign-busses" in the first place? This is likely a different issue, but if "pci=assign-busses" fixes something, I consider that a bug in itself, because Linux should be smart enough to do the right thing even without "pci=assign-busses". So if something on your machine requires "pci=assign-busses" in order to work, please open a second bugzilla for that. It's possible this is the same problem reported at https://bugzilla.kernel.org/show_bug.cgi?id=83441. We think that is related to fc1b253141b3 ("PCI: Don't scan random busses in pci_scan_bridge()"), which appeared in v3.15. I attached a test patch to that bugzilla to revert that commit. If you think it looks like the same problem, you might try testing that patch. Thanks again, Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
