VT-d: DMAR device scope parse fixup

Previously applied sanity check fixup is incorrect.

Signed-off-by: Espen Skoglund <espen.skoglund@netronome.com>

diff --git a/xen/drivers/passthrough/vtd/dmar.c b/xen/drivers/passthrough/vtd/dmar.c
index 19d5675a1b6dd2e39f2ba20cc75fcee977e932f9..0685d84010cb546774d11d3aab7520881e2bc69a 100644 (file)
--- a/xen/drivers/passthrough/vtd/dmar.c
+++ b/xen/drivers/passthrough/vtd/dmar.c
@@ -231,7 +231,7 @@ static int scope_device_count(void *start, void *end)
         bus = scope->start_bus;
         depth = (scope->length - sizeof(struct acpi_dev_scope))
                    / sizeof(struct acpi_pci_path);
-        while ( --depth >= 0 )
+        while ( --depth > 0 )
         {
             bus = read_pci_config_byte(
                 bus, path->dev, path->fn, PCI_SECONDARY_BUS);
@@ -353,7 +353,7 @@ static int __init acpi_parse_dev_scope(
                    / sizeof(struct acpi_pci_path);
         bus = scope->start_bus;
 
-        while ( --depth >= 0 )
+        while ( --depth > 0 )
         {
             bus = read_pci_config_byte(
                 bus, path->dev, path->fn, PCI_SECONDARY_BUS);