[RFC 2/9] xHCI 1.0: Control endpoint average TRB length field set

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xHCI 1.0 specification indicates that software should set Average TRB Length
to '8' for control endpoints.

Signed-off-by: Andiry Xu <andiry.xu@xxxxxxx>
---
 drivers/usb/host/xhci-mem.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index a4fc4d9..543833b 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1246,8 +1246,15 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
 	 * including link TRBs, No-op TRBs, and Event data TRBs.  Since we don't
 	 * use Event Data TRBs, and we don't chain in a link TRB on short
 	 * transfers, we're basically dividing by 1.
+	 *
+	 * xHCI 1.0 specification indicates that the Average TRB Length should
+	 * be set to 8 for control endpoints.
 	 */
-	ep_ctx->tx_info |= cpu_to_le32(AVG_TRB_LENGTH_FOR_EP(max_esit_payload));
+	if (usb_endpoint_xfer_control(&ep->desc) && xhci->hci_version == 0x100)
+		ep_ctx->tx_info |= cpu_to_le32(AVG_TRB_LENGTH_FOR_EP(8));
+	else
+		ep_ctx->tx_info |=
+			 cpu_to_le32(AVG_TRB_LENGTH_FOR_EP(max_esit_payload));
 
 	/* FIXME Debug endpoint context */
 	return 0;
-- 
1.7.1



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