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authorChunfeng Yun <chunfeng.yun@mediatek.com>2015-12-04 15:53:43 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-12-04 08:19:55 -0800
commit096b110a3dd3c868e4610937c80d2e3f3357c1a9 (patch)
tree32acd569fcf726bc5b8bb5171d8a33d37cb563ad
parent84ed91526f9881886d70a082032236edaa20e7d4 (diff)
usb: xhci: fix config fail of FS hub behind a HS hub with MTT
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@mediatek.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/host/xhci.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index dfa44d3e8eee..3f912705dcef 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4778,8 +4778,16 @@ int xhci_update_hub_device(struct usb_hcd *hcd, struct usb_device *hdev,
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",