USB 3.2 specification adds Dual-lane support, doubling the maximum
SuperSpeedPlus data rate from 10Gbps to 20Gbps.
Dual-lane takes into use a second set of rx and tx wires/pins in the
Type-C cable and connector.
Add "rx_lanes" and "tx_lanes" variables to struct usb_device to store
the numer of lanes in use. Number of lanes can be read using the extended
port status hub request that was introduced in USB 3.1.
Extended port status rx and tx lane count are zero based, maximum
lanes supported by non inter-chip (SSIC) USB 3.2 is 2 (dual lane) with
rx and tx lane count symmetric. SSIC devices support asymmetric lanes
up to 4 lanes per direction.
If extended port status is not available then default to one lane.
Signed-off-by: Mathias Nyman <mathias.ny...@linux.intel.com>
---
drivers/usb/core/hub.c | 8 ++++++++
include/linux/usb.h | 4 ++++
include/uapi/linux/usb/ch11.h | 5 +++++
3 files changed, 17 insertions(+)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index f6ea16e..97ee2f9 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2746,6 +2746,14 @@ static int hub_port_wait_reset(struct usb_hub *hub, int
port1,
if (!udev)
return 0;
+ if (hub_is_superspeedplus(hub->hdev)) {
+ /* extended portstatus Rx and Tx lane count are zero based */
+ udev->rx_lanes = USB_EXT_PORT_RX_LANES(ext_portstatus) + 1;
+ udev->tx_lanes = USB_EXT_PORT_TX_LANES(ext_portstatus) + 1;
+ } else {
+ udev->rx_lanes = 1;
+ udev->tx_lanes = 1;
+ }
if (hub_is_wusb(hub))
udev->speed = USB_SPEED_WIRELESS;
else if (hub_is_superspeedplus(hub->hdev) &&
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 0173597..beffcee 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -551,6 +551,8 @@ struct usb3_lpm_parameters {
* @route: tree topology hex string for use with xHCI
* @state: device state: configured, not attached, etc.
* @speed: device speed: high/full/low (or error)
+ * @rx_lanes: number of rx lanes in use, USB 3.2 adds dual-lane support
+ * @tx_lanes: number of tx lanes in use, USB 3.2 adds dual-lane support
* @tt: Transaction Translator info; used with low/full speed dev, highspeed
hub
* @ttport: device port on that tt hub
* @toggle: one bit for each endpoint, with ([0] = IN, [1] = OUT) endpoints
@@ -624,6 +626,8 @@ struct usb_device {
u32 route;
enum usb_device_state state;
enum usb_device_speed speed;
+ unsigned int rx_lanes;
+ unsigned int tx_lanes;
struct usb_tt *tt;
int ttport;
diff --git a/include/uapi/linux/usb/ch11.h b/include/uapi/linux/usb/ch11.h
index 29c120c..fb0cd24 100644
--- a/include/uapi/linux/usb/ch11.h
+++ b/include/uapi/linux/usb/ch11.h
@@ -197,6 +197,11 @@ struct usb_port_status {
#define USB_EXT_PORT_STAT_RX_LANES 0x00000f00
#define USB_EXT_PORT_STAT_TX_LANES 0x0000f000
+#define USB_EXT_PORT_RX_LANES(p) \
+ (((p) & USB_EXT_PORT_STAT_RX_LANES) >> 8)
+#define USB_EXT_PORT_TX_LANES(p) \
+ (((p) & USB_EXT_PORT_STAT_TX_LANES) >> 12)
+
/*
* wHubCharacteristics (masks)
* See USB 2.0 spec Table 11-13, offset 3
--
2.7.4
--
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