It was observed that on Intel MinnowMax board, when xHCI is enabled in the BayTrail SoC, with a USB 3.0 device connected to the bottom USB 3.0 port (mapped to xHCI root port #7), its PORTSC register is always 0x201203 (CCS = 1, CSC = 0). The root cause of such behavior is unknown yet. Connect status change bit is set on the same port with a USB 2.0 device (mapped to xHCI port #1, which is a different port on the root hub).
With current logic in usb_scan_port(), the enumeration process will abort if it does not detect a connect status change on a hub port. However since a device connection status is correctly reported, the enumeration process can still continue.
With this change, USB device connected to the bottom blue port on MinnowMax board can be enumerated under either SS or HS mode.
Signed-off-by: Bin Meng bmeng.cn@gmail.com Reviewed-by: Stefan Roese sr@denx.de Tested-by: Stefan Roese sr@denx.de Tested-by: Dinh Nguyen dinguyen@kernel.org ---
Changes in v2: None
common/usb_hub.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/common/usb_hub.c b/common/usb_hub.c index ff9cd50..8279e5c 100644 --- a/common/usb_hub.c +++ b/common/usb_hub.c @@ -408,8 +408,15 @@ static int usb_scan_port(struct usb_device_scan *usb_scan) portchange = le16_to_cpu(portsts->wPortChange); debug("Port %d Status %X Change %X\n", i + 1, portstatus, portchange);
- /* No connection change happened, wait a bit more. */ - if (!(portchange & USB_PORT_STAT_C_CONNECTION)) { + /* + * No connection change happened, wait a bit more. + * + * For some situation, the hub reports no connection change but a + * device is connected to the port (eg: CCS bit is set but CSC is not + * in the PORTSC register of a root hub), ignore such case. + */ + if (!(portchange & USB_PORT_STAT_C_CONNECTION) && + !(portstatus & USB_PORT_STAT_CONNECTION)) { if (get_timer(0) >= hub->connect_timeout) { debug("devnum=%d port=%d: timeout\n", dev->devnum, i + 1); @@ -421,10 +428,6 @@ static int usb_scan_port(struct usb_device_scan *usb_scan) return 0; }
- /* Test if the connection came up, and if not exit */ - if (!(portstatus & USB_PORT_STAT_CONNECTION)) - return 0; - /* A new USB device is ready at this point */ debug("devnum=%d port=%d: USB dev found\n", dev->devnum, i + 1);