Alex Williamson wrote: > On Thu, 2014-10-23 at 18:00 +0200, Andreas Hartmann wrote: >> Alex Williamson wrote: >>> On Wed, 2014-10-22 at 18:22 +0200, Andreas Hartmann wrote: >>>> Alex Williamson wrote: >>>>> --- a/drivers/pci/pci.c >>>>> +++ b/drivers/pci/pci.c >>>>> @@ -3308,15 +3308,15 @@ static int __pci_dev_reset(struct pci_dev *dev, int prob >>>>> if (rc != -ENOTTY) >>>>> goto done; >>>>> >>>>> - rc = pci_pm_reset(dev, probe); >>>>> + rc = pci_dev_reset_slot_function(dev, probe); >>>>> if (rc != -ENOTTY) >>>>> goto done; >>>>> >>>>> - rc = pci_dev_reset_slot_function(dev, probe); >>>>> + rc = pci_parent_bus_reset(dev, probe); >>>>> if (rc != -ENOTTY) >>>>> goto done; >>>>> >>>>> - rc = pci_parent_bus_reset(dev, probe); >>>>> + rc = pci_pm_reset(dev, probe); >>>>> done: >>>>> return rc; >>>>> } >>>> >>>> This way it's crashing with echo 1 > reset, too. >>> >>> Ok, so it's somehow related to doing a bus reset with virtual channel >>> save/restore while PM reset with VC save/restore works ok as apparently >>> does bus reset without VC save/restore. Let's try to do a manual bus >>> reset so we can look at the post reset state of the device before the >>> kernel tries to restore it. >>> >>> First bind the target device 03:00.0 to pci-stub or vfio-pci so that we >>> know it's not being used. >>> >>> Next capture lspci -xxxx -s 3:00.0 so we have the starting state. >>> >>> Then we'll do a bus reset using setpci: >>> # setpci -s 00:05.0 3e.w=40:40 >>> <if you script this, wait at least 2ms here> >>> # setpci -s 00:05.0 3e.w=00:40 >>> <wait 1 second here> >>> >>> Now re-capture lspci -xxxx -s 3:00.0 >> >> The machine is booted w/ vfio bound to 3:00.0 as usual (now for testing >> linux 3.14) >> >> lspci -xxxx -s 3:00.0 >> setpci -s 00:05.0 3e.w=40:40 >> usleep 10 >> setpci -s 00:05.0 3e.w=00:40 >> sleep 1 >> lspci -xxxx -s 3:00.0 >> >> I didn't get the second lspci because the machine already was hanging. >> The first output is attached completely. > > Hmm, that doesn't make much sense. You had found that if you disabled > the VC save/restore then QEMU works. That should have still been using > secondary bus reset as we're trying to do here, so I don't understand > why we can't do a manual secondary bus reset now. > > If you use Bjorn's previous patch to disable VC save/restore and my > patch to reorder the reset mechanisms, does echo 1 > reset for the sysfs > entry for the device also still cause a hang? I will test it. > Can you provide a link to the specific model for this card? Thanks, http://www.tp-link.com.de/support/download/?model=TL-WDN4800&version=V1 Regards, Andreas -- 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
