From: Bin Meng Date: Thu, 24 May 2018 06:40:49 +0000 (-0700) Subject: usb: xhci: Fix config fail of FS hub behind a HS hub with MTT X-Git-Tag: v2018.07-rc1~15^2~21 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=eaaefb066c86f08fb285e73fb8c5fbf497be6b57;p=platform%2Fkernel%2Fu-boot.git 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. In the case, we should clear MTT to 0 for full speed hub according to section 6.2.2. This keeps in sync with Linux kernel commit: 096b110: usb: xhci: fix config fail of FS hub behind a HS hub with MTT Signed-off-by: Bin Meng --- diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 8c1126e..f9c6bbb 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -1435,8 +1435,15 @@ static int xhci_update_hub_device(struct udevice *dev, struct usb_device *udev) /* Update hub related fields */ slot_ctx->dev_info |= cpu_to_le32(DEV_HUB); - if (hub->tt.multi && udev->speed == USB_SPEED_HIGH) + /* + * 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 (hub->tt.multi) slot_ctx->dev_info |= cpu_to_le32(DEV_MTT); + else if (udev->speed == USB_SPEED_FULL) + slot_ctx->dev_info &= cpu_to_le32(~DEV_MTT); slot_ctx->dev_info2 |= cpu_to_le32(XHCI_MAX_PORTS(udev->maxchild)); /* * Set TT think time - convert from ns to FS bit times.