[coreboot-gerrit] Patch set updated for coreboot: ebdc655 libpayload: usb: xhci: set ENT flag in last Normal TRB

[Patrick Georgi (pgeorgi@google.com)]

Patrick Georgi (pgeorgi at google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/8736

-gerrit

commit ebdc65516e13a35fc946640ca68c6295d7e19a39
Author: Sourabh Banerjee <sbanerje at codeaurora.org>
Date:   Wed Sep 24 16:14:45 2014 +0530

    libpayload: usb: xhci: set ENT flag in last Normal TRB
    
    If a TD is comprised of one or more Normal TRBs and terminated with an
    Event Data TRB, then the transition to the Idle state (and associated
    Stream state save) could occur after all the data for the TD has been
    moved (e.g. after Transfer Event TRBs have been executed), but before the
    Event Data TRB is executed. Under these conditions, the execution of the
    Event Data TRB is necessary to complete the TD, otherwise it does not
    occur until the next time the Stream is scheduled. This could lead to the
    lock up.
    
    The Evaluate Next TRB(ENT) flag provides a means of forcing the execution
    of a terminating Event Data TRB. Setting ENT flag in last Normal TRB makes
    the xHC to evaluate the Even Data TRB.
    
    BUG=chrome-os-partner:29375
    TEST=Verified kernel boot-up on storm from previously failing USB stick.
         USB stick model: Sandisk Ultra USB 3.0 Pen Drive 32 GB
    		      Strontium Jet USB 3.0 Pen Drive 32 GB
    
    Change-Id: I092e2109c55c2274239c493cb67b47d730304ed2
    Signed-off-by: Patrick Georgi <pgeorgi at chromium.org>
    Original-Commit-Id: 7eefb3b2858c841165ae839d349d2a0be50fbcc8
    Original-Change-Id: I4e123577ec5a5996d87d2fc52cb6cf5c571c9fae
    Original-Signed-off-by: Sourabh Banerjee <sbanerje at codeaurora.org>
    Original-Reviewed-on: https://chromium-review.googlesource.com/220123
    Original-Reviewed-by: Julius Werner <jwerner at chromium.org>
    Original-Commit-Queue: Vadim Bendebury <vbendeb at chromium.org>
    Original-Tested-by: Vadim Bendebury <vbendeb at chromium.org>
---
 payloads/libpayload/drivers/usb/xhci.c         | 8 ++++++++
 payloads/libpayload/drivers/usb/xhci_private.h | 3 +++
 2 files changed, 11 insertions(+)

diff --git a/payloads/libpayload/drivers/usb/xhci.c b/payloads/libpayload/drivers/usb/xhci.c
index 33009bc..7adb304 100644
--- a/payloads/libpayload/drivers/usb/xhci.c
+++ b/payloads/libpayload/drivers/usb/xhci.c
@@ -551,6 +551,14 @@ xhci_enqueue_td(transfer_ring_t *const tr, const int ep, const size_t mps,
 		} else {
 			TRB_SET(TT, trb, TRB_NORMAL);
 		}
+		/*
+		 * This is a workaround for Synopsys DWC3. If the ENT flag is
+		 * not set for the Normal and Data Stage TRBs. We get Event TRB
+		 * with length 0x20d from the controller when we enqueue a TRB
+		 * for the IN endpoint with length 0x200.
+		 */
+		if (!length)
+			TRB_SET(ENT, trb, 1);
 
 		xhci_enqueue_trb(tr);
 
diff --git a/payloads/libpayload/drivers/usb/xhci_private.h b/payloads/libpayload/drivers/usb/xhci_private.h
index 43800d8..3861858 100644
--- a/payloads/libpayload/drivers/usb/xhci_private.h
+++ b/payloads/libpayload/drivers/usb/xhci_private.h
@@ -93,6 +93,9 @@ enum { TRB_DIR_OUT = 0, TRB_DIR_IN = 1 };
 #define TRB_TC_FIELD		control		/* TC - Toggle Cycle */
 #define TRB_TC_START		1
 #define TRB_TC_LEN		1
+#define TRB_ENT_FIELD		control		/* ENT - Evaluate Next TRB */
+#define TRB_ENT_START		1
+#define TRB_ENT_LEN		1
 #define TRB_ISP_FIELD		control		/* ISP - Interrupt-on Short Packet */
 #define TRB_ISP_START		2
 #define TRB_ISP_LEN		1