[coreboot-gerrit] New patch to review for coreboot: libpayload: usbmsc: Add small delay during initialization to fix CZ60

[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/12229

-gerrit

commit 7435801568b544722874655e88a923e15cfcfe2b
Author: Julius Werner <jwerner at chromium.org>
Date:   Mon Oct 26 11:44:00 2015 -0700

    libpayload: usbmsc: Add small delay during initialization to fix CZ60
    
    We found that some SanDisk Cruizer Glide CZ60 sticks (confirmed on 16GB
    and 64GB versions) have a problem responding to our first GET_MAX_LUNS
    request right after they received their SET_CONFIGURATION. They will
    continually return a NAK until the host gives up (which is 2
    user-noticable seconds for us). Adding a small delay of about 15us seems
    to be enough to fix the issue, but let's do 50 to be save.
    
    Confirmed with both MT8173 and Intel LynxPoint XHCI controllers.
    
    BRANCH=None
    BUG=chrome-os-partner:45473
    TEST=No notable delay before detecting stick on Oak and Falco.
    
    Change-Id: Ib03944d6484de0ccecbb9922d22666f54c9d53dd
    Signed-off-by: Patrick Georgi <pgeorgi at chromium.org>
    Original-Commit-Id: 589f19a901275fb8b00de4595763a7d577bed524
    Original-Change-Id: I95c79fe40d3ad79f37ce2eb586836e5de55be454
    Original-Signed-off-by: Julius Werner <jwerner at chromium.org>
    Original-Reviewed-on: https://chromium-review.googlesource.com/308980
    Original-Reviewed-by: Patrick Georgi <pgeorgi at chromium.org>
---
 payloads/libpayload/drivers/usb/usbmsc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/payloads/libpayload/drivers/usb/usbmsc.c b/payloads/libpayload/drivers/usb/usbmsc.c
index ccd693a..17313cf 100644
--- a/payloads/libpayload/drivers/usb/usbmsc.c
+++ b/payloads/libpayload/drivers/usb/usbmsc.c
@@ -660,6 +660,9 @@ usb_msc_init (usbdev_t *dev)
 		MSC_INST (dev)->bulk_in->endpoint,
 		MSC_INST (dev)->bulk_out->endpoint);
 
+	/* Some sticks need a little more time to get ready after SET_CONFIG. */
+	udelay(50);
+
 	initialize_luns (dev);
 	usb_debug ("  has %d luns\n", MSC_INST (dev)->num_luns);