[+cc kexec] On 5/25/2018 7:04 AM, Sinan Kaya wrote: > It is up to a driver to implement shutdown() callback. If shutdown() > callback is not implemented, PCI device can have pending interrupt and > even do DMA transactions while the system is going down. > > If kexec is in use, this can damage the newly booting kexec kernel > or even prevent it from booting altogether. Fallback to calling the > remove() callback if shutdown() isn't implemented for a given driver. > > Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx> > --- > drivers/pci/pci-driver.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index 6ace470..4ac72e3 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -475,8 +475,17 @@ static void pci_device_shutdown(struct device *dev) > > pm_runtime_resume(dev); > > + /* > + * Try shutdown callback if it exists, otherwise fallback to remove > + * callback. PCI drivers can do DMA and have pending interrupts. > + * Leaving the DMA and interrupts pending could damage the newly > + * booting kexec kernel as well as prevent it from booting altogether > + * if the pending interrupt is level. > + */ > if (drv && drv->shutdown) > drv->shutdown(pci_dev); > + else if (drv && drv->remove) > + drv->remove(pci_dev); > > /* > * If this is a kexec reboot, turn off Bus Master bit on the > -- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
