| Message ID | 1527011883-21320-1-git-send-email-okaya@codeaurora.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | Andy Gross |
| Headers | show |
On 05/22/2018 10:58 AM, Sinan Kaya wrote: > 'Commit cc27b735ad3a ("PCI/portdrv: Turn off PCIe services during > shutdown")' has been added to kernel to shutdown pending PCIe port > service interrupts during reboot so that a newly started kexec kernel > wouldn't observe pending interrupts. > > pcie_port_device_remove() is disabling the root port and switches by > calling pci_disable_device() after all PCIe service drivers are shutdown. > > pci_disable_device() has a much wider impact then port service itself and > it prevents all inbound transactions to reach to the system and impacts > the entire PCI traffic behind the bridge. > > Issue is that pcie_port_device_remove() doesn't maintain any coordination > with the rest of the PCI device drivers in the system before clearing the > bus master bit. > > This has been found to cause crashes on HP DL360 Gen9 machines during > reboot. Besides, kexec is already clearing the bus master bit in > pci_device_shutdown() after all PCI drivers are removed. FAOD, this problem has been observed on both DL360 Gen9 and DL380 Gen9, in both EFI and legacy modes. I suspect all Gen9 models with the P89 firmware base. > Just remove the extra clear here. Thank you! Fix tested on: - DL360 Gen9 - DL380 Gen9 - DL380 Gen10 (confirmed no regression) - DL380 G7 (confirmed no regression) > Signed-off-by: Sinan Kaya <okaya@codeaurora.org> > Link: https://bugzilla.kernel.org/show_bug.cgi?id=199779 > Fixes: cc27b735ad3a ("PCI/portdrv: Turn off PCIe services during shutdown") > Cc: stable@vger.kernel.org > Reported-by: Ryan Finnie <ryan@finnie.org> Tested-by: Ryan Finnie <ryan@finnie.org> -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, May 22, 2018 at 01:58:00PM -0400, Sinan Kaya wrote: > --- a/drivers/pci/pcie/portdrv_core.c > +++ b/drivers/pci/pcie/portdrv_core.c > @@ -409,7 +409,6 @@ void pcie_port_device_remove(struct pci_dev *dev) > { > device_for_each_child(&dev->dev, NULL, remove_iter); > pci_free_irq_vectors(dev); > - pci_disable_device(dev); > } Shutdown aside, pci_disable_device() is also not called in the ->remove path with this patch, right? Seems wrong. E.g. when unbinding the driver from the root port device, or when unplugging a port (happens all the time with Thunderbolt). Thanks, Lukas -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 5/22/2018 10:24 PM, Lukas Wunner wrote: > On Tue, May 22, 2018 at 01:58:00PM -0400, Sinan Kaya wrote: >> --- a/drivers/pci/pcie/portdrv_core.c >> +++ b/drivers/pci/pcie/portdrv_core.c >> @@ -409,7 +409,6 @@ void pcie_port_device_remove(struct pci_dev *dev) >> { >> device_for_each_child(&dev->dev, NULL, remove_iter); >> pci_free_irq_vectors(dev); >> - pci_disable_device(dev); >> } > > Shutdown aside, pci_disable_device() is also not called in the ->remove > path with this patch, right? Seems wrong. E.g. when unbinding the driver > from the root port device, or when unplugging a port (happens all the time > with Thunderbolt). Agreed. I'll spin another version where I skip disable on shutdown path only. > > Thanks, > > Lukas >
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index c9c0663..d22a95d 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -409,7 +409,6 @@ void pcie_port_device_remove(struct pci_dev *dev) { device_for_each_child(&dev->dev, NULL, remove_iter); pci_free_irq_vectors(dev); - pci_disable_device(dev); } /**
'Commit cc27b735ad3a ("PCI/portdrv: Turn off PCIe services during shutdown")' has been added to kernel to shutdown pending PCIe port service interrupts during reboot so that a newly started kexec kernel wouldn't observe pending interrupts. pcie_port_device_remove() is disabling the root port and switches by calling pci_disable_device() after all PCIe service drivers are shutdown. pci_disable_device() has a much wider impact then port service itself and it prevents all inbound transactions to reach to the system and impacts the entire PCI traffic behind the bridge. Issue is that pcie_port_device_remove() doesn't maintain any coordination with the rest of the PCI device drivers in the system before clearing the bus master bit. This has been found to cause crashes on HP DL360 Gen9 machines during reboot. Besides, kexec is already clearing the bus master bit in pci_device_shutdown() after all PCI drivers are removed. Just remove the extra clear here. Signed-off-by: Sinan Kaya <okaya@codeaurora.org> Link: https://bugzilla.kernel.org/show_bug.cgi?id=199779 Fixes: cc27b735ad3a ("PCI/portdrv: Turn off PCIe services during shutdown") Cc: stable@vger.kernel.org Reported-by: Ryan Finnie <ryan@finnie.org> --- drivers/pci/pcie/portdrv_core.c | 1 - 1 file changed, 1 deletion(-)