On Tue, Apr 22, 2014 at 03:07:28PM +0800, Jiang Liu wrote: > Finally enhance pci_root driver to support DMAR device hotplug when > hot-plugging PCI host bridges. > > Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx> > --- > drivers/acpi/pci_root.c | 16 ++++++++++++++-- > 1 file changed, 14 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c > index d388f13d48b4..aa8f549869f3 100644 > --- a/drivers/acpi/pci_root.c > +++ b/drivers/acpi/pci_root.c > @@ -33,6 +33,7 @@ > #include <linux/pci.h> > #include <linux/pci-acpi.h> > #include <linux/pci-aspm.h> > +#include <linux/dmar.h> > #include <linux/acpi.h> > #include <linux/slab.h> > #include <acpi/apei.h> /* for acpi_hest_init() */ > @@ -511,6 +512,7 @@ static int acpi_pci_root_add(struct acpi_device *device, > struct acpi_pci_root *root; > acpi_handle handle = device->handle; > int no_aspm = 0, clear_aspm = 0; > + bool hotadd = (system_state != SYSTEM_BOOTING); > > root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL); > if (!root) > @@ -557,6 +559,11 @@ static int acpi_pci_root_add(struct acpi_device *device, > strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS); > device->driver_data = root; > > + if (hotadd && dmar_device_hotplug(handle, true)) { Apparently "dmar_device_hotplug(handle, true)" means "add a DMAR device," and "dmar_device_hotplug(device->handle, false)" means "remove a DMAR device." I'm not really a fan of interfaces where one of the arguments selects between two completely different actions, because it's harder for a casual reader to see what's going on. I see how it simplifies your implementation a little bit, but I think it's more important to simplify for the reader. Bjorn -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html