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authorSarah Sharp <sarah.a.sharp@linux.intel.com>2011-04-08 09:37:29 -0700
committerSarah Sharp <sarah.a.sharp@linux.intel.com>2011-05-02 16:42:56 -0700
commit5cd43e33b9519143f06f507dd7cbee6b7a621885 (patch)
tree21613030a78a24dab98cbcffd3a59c4d8f111e8d /drivers/usb/host/xhci.h
parent4da6e6f247a2601ab9f1e63424e4d944ed4124f3 (diff)
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xhci 1.0: Set transfer burst count field.
The xHCI 1.0 specification adds a new field to the fourth dword in an isochronous TRB: the transfer burst count (TBC). This field is only non-zero for SuperSpeed devices. Each SS endpoint sets the bMaxBurst field in the SuperSpeed endpoint companion descriptor, which indicates how many max-packet-sized "bursts" it can handle in one service interval. The device driver may choose to burst less max packet sized chunks each service interval (which is defined by one TD). The xHCI driver indicates to the host controller how many bursts it needs to schedule through the transfer burst count field. This patch will only effect xHCI hosts that advertise 1.0 support (0x100) in the HCI version field of their capabilities register. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Diffstat (limited to 'drivers/usb/host/xhci.h')
-rw-r--r--drivers/usb/host/xhci.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 85e779808189..87ec3b079728 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -943,6 +943,7 @@ struct xhci_event_cmd {
/* Interrupter Target - which MSI-X vector to target the completion event at */
#define TRB_INTR_TARGET(p) (((p) & 0x3ff) << 22)
#define GET_INTR_TARGET(p) (((p) >> 22) & 0x3ff)
+#define TRB_TBC(p) (((p) & 0x3) << 7)
/* Cycle bit - indicates TRB ownership by HC or HCD */
#define TRB_CYCLE (1<<0)