Index: uspace/drv/bus/usb/xhci/hw_struct/context.h
===================================================================
--- uspace/drv/bus/usb/xhci/hw_struct/context.h	(revision eaf5e867c62f55c6dc6731c2cddfcdb4ba097009)
+++ uspace/drv/bus/usb/xhci/hw_struct/context.h	(revision 867b3757d6898c102509e02a34857fa95c832191)
@@ -166,4 +166,5 @@
 
 #define XHCI_INPUT_CTRL_CTX_DROP_SET(ctx, idx) (ctx).data[0] |= (1 << (idx))
+#define XHCI_INPUT_CTRL_CTX_DROP_CLEAR(ctx, idx) (ctx).data[0] &= ~(1 << (idx))
 
 #define XHCI_INPUT_CTRL_CTX_ADD(ctx, idx) \
@@ -171,4 +172,5 @@
 
 #define XHCI_INPUT_CTRL_CTX_ADD_SET(ctx, idx) (ctx).data[1] |= (1 << (idx))
+#define XHCI_INPUT_CTRL_CTX_ADD_CLEAR(ctx, idx) (ctx).data[1] &= ~(1 << (idx))
 
 #define XHCI_INPUT_CTRL_CTX_CONFIG_VALUE(ctx)   XHCI_DWORD_EXTRACT((ctx).data[7],  7,  0)