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USB: Add support to store lane count used by USB 3.2

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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.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathias Nyman
2018-04-19 19:05:51 +03:00
committed by Greg Kroah-Hartman
parent ffe95371d2
commit 013eedb8c5
3 changed files with 17 additions and 0 deletions
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5
include/uapi/linux/usb/ch11.h
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@@ -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