On Friday, June 28, 2013 09:22:32 AM Yinghai Lu wrote: > On Fri, Jun 28, 2013 at 2:33 AM, Kirill A. Shutemov > <kirill.shutemov@xxxxxxxxxxxxxxx> wrote: > > Yinghai Lu wrote: > >> On Tue, Jun 25, 2013 at 9:22 AM, Mika Westerberg > >> <mika.westerberg@xxxxxxxxxxxxxxx> wrote: > >> > From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> > >> > > >> > Current acpiphp_check_bridge() implementation is pretty dumb: > >> > - it enables the slot if it's not enabled and the slot status is > >> > ACPI_STA_ALL; > >> > - it disables the slot if it's enabled and slot is not in ACPI_STA_ALL > >> > state. > >> > > >> > This behavior is not enough to handle Thunderbolt chaining case > >> > properly. We need to actually rescan for new devices even if a device > >> > has already in the slot. > >> > > >> > The new implementation disables and stops the slot if it's not in > >> > ACPI_STA_ALL state. > >> > > >> > For ACPI_STA_ALL state we first trim devices which don't respond and > >> > look for the ones after that. We do that even if slot already enabled > >> > (SLOT_ENABLED). > >> > >> that is not right, some time BUS_CHECK is even sent root bus. > >> in that case, stop all devices in slots and load driver again. > >> > >> like you put one card in one slots, but all devices in other slots get stop > >> and enable again. > > > > We don't stop enabled devices, we only stop and remove devices which don't > > respond. See patch 3/6. > > > > I don't see how it's harmful. Do you? > > then please check with disable_device to put back pci_dev ref, > also may need to trim corresponding acpi devices. That's correct. Thunderbolt may not need that, but ACPI device objects need to be trimmed too in general. > so this patch is helping: multiple plug-in and remove? I think it helps the case when a Thunderbolt device is removed and we only get a bus check notify for the controller after the fact. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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
