libpayload: Increase USB EHCI transfer timeout

The EHCI driver defines a maximum transfer timeout of two seconds. The
comments state that during tests the maximum amount of required transfer
time was for the SCSI TEST_UNIT_READY command on certain devices. We
have now observed a USB device (Patriot Memory 13fe:3100) that can NAK
this command for slightly more than two seconds. It will also completely
fail if the timeout hits, since it gets confused by the subsequent CSW
retry/recovery mechanism and starts producing babble errors. This patch
increases the timeout to three seconds to circumvent this problem.

To test, boot a Falco from a red-black RageXT USB stick.

Change-Id: I3c4fef468fb16eacc5a487d76d025a78fb450e27
Signed-off-by: Julius Werner <>
Reviewed-by: Aaron Durbin <>
Reviewed-by: Duncan Laurie <>
Reviewed-by: Sameer Nanda <>
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <>
diff --git a/payloads/libpayload/drivers/usb/ehci.c b/payloads/libpayload/drivers/usb/ehci.c
index e61e806..e58bd38 100644
--- a/payloads/libpayload/drivers/usb/ehci.c
+++ b/payloads/libpayload/drivers/usb/ehci.c
@@ -279,12 +279,12 @@
 		/* how long to wait?
 		 * tested with some USB2.0 flash sticks:
 		 * TUR turn around took
-		 *   about 2s for the slowest (14cd:121c)
+		 *   about 2.2s for the slowest (13fe:3800)
 		 *   max. 250ms for the others
 		 * slowest non-TUR turn around took about 1.3s
-		 * try 2s for now as a failed TUR is not fatal
+		 * set to 3s to be safe as a failed TUR can be fatal
-		int timeout = 40000; /* time out after 40000 * 50us == 2s */
+		int timeout = 60000; /* time out after 60000 * 50us == 3s */
 		while ((cur->token & QTD_ACTIVE) && !(cur->token & QTD_HALTED)
 				&& timeout--)