On 2014/4/25 1:33, Bjorn Helgaas wrote: > 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. Thanks Bjorn, I will rename it to dmar_device_add/remove() instead. > > 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