This is a note to let you know that I've just added the patch titled
usb: xhci: fix config fail of FS hub behind a HS hub with MTT
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-xhci-fix-config-fail-of-fs-hub-behind-a-hs-hub-with-mtt.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 096b110a3dd3c868e4610937c80d2e3f3357c1a9 Mon Sep 17 00:00:00 2001
From: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
Date: Fri, 4 Dec 2015 15:53:43 +0200
Subject: usb: xhci: fix config fail of FS hub behind a HS hub with MTT
From: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
commit 096b110a3dd3c868e4610937c80d2e3f3357c1a9 upstream.
if a full speed hub connects to a high speed hub which
supports MTT, the MTT field of its slot context will be set
to 1 when xHCI driver setups an xHCI virtual device in
xhci_setup_addressable_virt_dev(); once usb core fetch its
hub descriptor, and need to update the xHC's internal data
structures for the device, the HUB field of its slot context
will be set to 1 too, meanwhile MTT is also set before,
this will cause configure endpoint command fail, so in the
case, we should clear MTT to 0 for full speed hub according
to section 6.2.2
Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4615,8 +4615,16 @@ int xhci_update_hub_device(struct usb_hc
ctrl_ctx->add_flags |= cpu_to_le32(SLOT_FLAG);
slot_ctx = xhci_get_slot_ctx(xhci, config_cmd->in_ctx);
slot_ctx->dev_info |= cpu_to_le32(DEV_HUB);
+ /*
+ * refer to section 6.2.2: MTT should be 0 for full speed hub,
+ * but it may be already set to 1 when setup an xHCI virtual
+ * device, so clear it anyway.
+ */
if (tt->multi)
slot_ctx->dev_info |= cpu_to_le32(DEV_MTT);
+ else if (hdev->speed == USB_SPEED_FULL)
+ slot_ctx->dev_info &= cpu_to_le32(~DEV_MTT);
+
if (xhci->hci_version > 0x95) {
xhci_dbg(xhci, "xHCI version %x needs hub "
"TT think time and number of ports\n",
Patches currently in stable-queue which might be from chunfeng.yun@xxxxxxxxxxxx are
queue-3.10/usb-xhci-fix-config-fail-of-fs-hub-behind-a-hs-hub-with-mtt.patch
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