usb: Check for genXxY on host

Check for usb_device->ssp_rate to print the SuperSpeed Plus signaling rate generation and lane count.

Signed-off-by Thinh Nguyen <[email protected]>

---
Changes in v2:
- None

 drivers/usb/core/hub.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

drivers/usb/core/hub.c +0 -0

index 823470607d58..6dc4e7385e75 100644
@@ -4830,9 +4830,13 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
 						"%s SuperSpeed%s%s USB device number %d using %s\n",
 						(udev->config) ? "reset" : "new",
 					 (udev->speed == USB_SPEED_SUPER_PLUS) ?

Quoted 23 lines · Thinh Nguyen

Check for usb_device->ssp_rate to print the SuperSpeed Plus signaling rate generation and lane count.

Signed-off-by Thinh Nguyen <[email protected]>

---
Changes in v2:
- None

 drivers/usb/core/hub.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

drivers/usb/core/hub.c +1 -3

index 823470607d58..6dc4e7385e75 100644
@@ -4830,9 +4830,13 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
 						"%s SuperSpeed%s%s USB device number %d using %s\n",
 						(udev->config) ? "reset" : "new",
 					 (udev->speed == USB_SPEED_SUPER_PLUS) ?
-							"Plus Gen 2" : " Gen 1",
-					 (udev->rx_lanes == 2 && udev->tx_lanes == 2) ?
-							"x2" : "",
+							" Plus" : "",

drivers/usb/core/hub.c hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1, · line 4839

Quoted 6 lines

drivers/usb/core/hub.c +6 -0

+					 (udev->ssp_rate == USB_SSP_GEN_2x2) ?
+							" gen2x2" :
+					 (udev->ssp_rate == USB_SSP_GEN_2x1) ?
+							" gen2x1" :
+					 (udev->ssp_rate == USB_SSP_GEN_1x2) ?
+							" gen1x2" : "",

Minor nit:
Should we keep the "Gen XxY" format used in spec and driver, instead of this "genXxY"

The current xhci_create_usb3_bos_desc() uses a static bos u8 array and various magic numbers and offsets making it difficult to extend support for USB 3.2. Let's rewrite this entire function to support dual-lane in USB 3.2.

The hub driver matches the port speed ID from the extended port status to the SSID of the sublink speed attributes to detect if the device supports SuperSpeed Plus. Currently we don't provide the default gen1x2 and gen2x2 sublink speed capability descriptor for USB 3.2 roothub. The USB stack depends on this to detect and match the correct speed. In addition, if the xHCI host provides Protocol Speed ID (PSI) capability, then make sure to convert Protocol Speed ID Mantissa and Exponent (PSIM & PSIE) to lane speed for gen1x2 and gen2x2.

Signed-off-by Thinh Nguyen <[email protected]>

---
Changes in v2:
- Use static array for SSA per Mathias suggestion
- Check bcdUSB >= 0x320 instead of bcdUSB == 0x320 per Mathias suggestion
- When host uses custom PSI, SSIC is the psi_uid_count and not SSAC. I missed this when transferring the previous logic over. Previous implementation was incorrect. Let's fix it here.

 drivers/usb/host/xhci-hub.c | 237 +++++++++++++++++++++++++++++++++++-
 1 file changed, 235 insertions(+), 2 deletions(-)

drivers/usb/host/xhci-hub.c +149 -1

index 74c497fd3476..eddd139c2260 100644
@@ -11,6 +11,7 @@
 
 #include <linux/slab.h>
 #include <asm/unaligned.h>
+#include <linux/bitfield.h>
 
 #include "xhci.h"
 #include "xhci-trace.h"

@@ -52,7 +53,239 @@ static u8 usb_bos_descriptor [] = {
 	0xb5, 0x40, 0x0a, 0x00,		/* 10Gbps, SSP, symmetric, tx, ID = 5 */
 };
 
-static int xhci_create_usb3_bos_desc(struct xhci_hcd *xhci, char *buf,
+/* Default sublink speed attribute of each lane */
+static u32 ssp_cap_default_ssa[] = {
+	0x00050034, /* USB 3.0 SS Gen1x1 id:4 symmetric rx 5Gbps */
+	0x000500b4, /* USB 3.0 SS Gen1x1 id:4 symmetric tx 5Gbps */
+	0x000a4035, /* USB 3.1 SSP Gen2x1 id:5 symmetric rx 10Gbps */
+	0x000a40b5, /* USB 3.1 SSP Gen2x1 id:5 symmetric tx 10Gbps */
+	0x00054036, /* USB 3.2 SSP Gen1x2 id:6 symmetric rx 5Gbps */
+	0x000540b6, /* USB 3.2 SSP Gen1x2 id:6 symmetric tx 5Gbps */
+	0x000a4037, /* USB 3.2 SSP Gen2x2 id:7 symmetric rx 10Gbps */
+	0x000a40b7, /* USB 3.2 SSP Gen2x2 id:7 symmetric tx 10Gbps */
+};
+
+static int xhci_create_usb3x_bos_desc(struct xhci_hcd *xhci, char *buf,
+				      u16 wLength)
+{
+	struct usb_bos_descriptor	*bos;
+	struct usb_ss_cap_descriptor	*ss_cap;
+	struct usb_ssp_cap_descriptor	*ssp_cap;
+	struct xhci_port_cap		*port_cap = NULL;
+	u16				bcdUSB;
+	u32				reg;
+	u32				min_rate = 0;
+	u8				min_ssid;
+	u8				ssac;
+	u8				ssic;
+	int				offset;
+	int				i;
+
+	/* BOS descriptor */
+	bos = (struct usb_bos_descriptor *)buf;
+	bos->bLength = USB_DT_BOS_SIZE;
+	bos->bDescriptorType = USB_DT_BOS;
+	bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE +
+					USB_DT_USB_SS_CAP_SIZE);
+	bos->bNumDeviceCaps = 1;
+
+	/* Create the descriptor for port with the highest revision */
+	for (i = 0; i < xhci->num_port_caps; i++) {
+		u8 major = xhci->port_caps[i].maj_rev;
+		u8 minor = xhci->port_caps[i].min_rev;
+		u16 rev = (major << 8) | minor;
+
+		if (i == 0 || bcdUSB < rev) {
+			bcdUSB = rev;
+			port_cap = &xhci->port_caps[i];
+		}
+	}
+
+	if (bcdUSB >= 0x0310) {
+		if (port_cap->psi_count) {
+			u8 num_sym_ssa = 0;
+
+			for (i = 0; i < port_cap->psi_count; i++) {
+				if ((port_cap->psi[i] & PLT_MASK) == PLT_SYM)
+					num_sym_ssa++;
+			}
+
+			ssac = port_cap->psi_count + num_sym_ssa - 1;
+			ssic = port_cap->psi_uid_count - 1;
+		} else {
+			if (bcdUSB >= 0x0320)
+				ssac = 7;
+			else
+				ssac = 3;
+
+			ssic = (ssac + 1) / 2 - 1;
+		}
+
+		bos->bNumDeviceCaps++;
+		bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE +
+						USB_DT_USB_SS_CAP_SIZE +
+						USB_DT_USB_SSP_CAP_SIZE(ssac));
+	}
+
+	if (wLength < USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE)
+		return wLength;
+
+	/* SuperSpeed USB Device Capability */
+	ss_cap = (struct usb_ss_cap_descriptor *)&buf[USB_DT_BOS_SIZE];
+	ss_cap->bLength = USB_DT_USB_SS_CAP_SIZE;
+	ss_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
+	ss_cap->bDevCapabilityType = USB_SS_CAP_TYPE;
+	ss_cap->bmAttributes = 0; /* set later */
+	ss_cap->wSpeedSupported = cpu_to_le16(USB_5GBPS_OPERATION);
+	ss_cap->bFunctionalitySupport = USB_LOW_SPEED_OPERATION;
+	ss_cap->bU1devExitLat = 0; /* set later */
+	ss_cap->bU2DevExitLat = 0; /* set later */
+
+	reg = readl(&xhci->cap_regs->hcc_params);
+	if (HCC_LTC(reg))
+		ss_cap->bmAttributes |= USB_LTM_SUPPORT;
+
+	if ((xhci->quirks & XHCI_LPM_SUPPORT)) {
+		reg = readl(&xhci->cap_regs->hcs_params3);
+		ss_cap->bU1devExitLat = HCS_U1_LATENCY(reg);
+		ss_cap->bU2DevExitLat = cpu_to_le16(HCS_U2_LATENCY(reg));
+	}
+
+	if (wLength < le16_to_cpu(bos->wTotalLength))
+		return wLength;
+
+	if (bcdUSB < 0x0310)
+		return le16_to_cpu(bos->wTotalLength);
+
+	ssp_cap = (struct usb_ssp_cap_descriptor *)&buf[USB_DT_BOS_SIZE +
+		USB_DT_USB_SS_CAP_SIZE];
+	ssp_cap->bLength = USB_DT_USB_SSP_CAP_SIZE(ssac);
+	ssp_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
+	ssp_cap->bDevCapabilityType = USB_SSP_CAP_TYPE;
+	ssp_cap->bReserved = 0;
+	ssp_cap->wReserved = 0;
+	ssp_cap->bmAttributes =
+		cpu_to_le32(FIELD_PREP(USB_SSP_SUBLINK_SPEED_ATTRIBS, ssac) |
+			    FIELD_PREP(USB_SSP_SUBLINK_SPEED_IDS, ssic));
+
+	if (!port_cap->psi_count) {
+		for (i = 0; i < ssac + 1; i++)
+			ssp_cap->bmSublinkSpeedAttr[i] =
+				cpu_to_le32(ssp_cap_default_ssa[i]);
+
+		min_ssid = 4;
+		goto out;
+	}
+
+	offset = 0;
+	for (i = 0; i < port_cap->psi_count; i++) {
+		u32 psi;
+		u32 attr;
+		u8 ssid;
+		u8 lp;
+		u8 lse;
+		u8 psie;
+		u16 lane_mantissa;
+		u16 psim;
+		u16 plt;
+
+		psi = port_cap->psi[i];
+		ssid = XHCI_EXT_PORT_PSIV(psi);
+		lp = XHCI_EXT_PORT_LP(psi);
+		psie = XHCI_EXT_PORT_PSIE(psi);
+		psim = XHCI_EXT_PORT_PSIM(psi);
+		plt = psi & PLT_MASK;
+
+		lse = psie;
+		lane_mantissa = psim;
+
+		/* Shift to Gbps and set SSP Link Protocol if 10Gpbs */
+		for (; psie < USB_SSP_SUBLINK_SPEED_LSE_GBPS; psie++)

drivers/usb/host/xhci-hub.c +17 -0

+
+		/*
+		 * PSIM and PSIE represent the total speed of PSI. The BOS
+		 * descriptor SSP sublink speed attribute lane mantissa
+		 * describes the lane speed. E.g. PSIM and PSIE for gen2x2
+		 * is 20Gbps, but the BOS descriptor lane speed mantissa is
+		 * 10Gbps. Check and modify the mantissa value to match the
+		 * lane speed.
+		 */
+		if (bcdUSB == 0x0320 && plt == PLT_SYM) {
+			/*
+			 * The PSI dword for gen1x2 and gen2x1 share the same
+			 * values. But the lane speed for gen1x2 is 5Gbps while
+			 * gen2x1 is 10Gbps. If the previous PSI dword SSID is
+			 * 5 and the PSIE and PSIM match with SSID 6, let's
+			 * assume that the controller follows the default speed
+			 * id with SSID 6 for gen1x2.

drivers/usb/host/xhci-hub.c +41 -0

+		}
+
+		attr = (FIELD_PREP(USB_SSP_SUBLINK_SPEED_SSID, ssid) |
+			FIELD_PREP(USB_SSP_SUBLINK_SPEED_LP, lp) |
+			FIELD_PREP(USB_SSP_SUBLINK_SPEED_LSE, lse) |
+			FIELD_PREP(USB_SSP_SUBLINK_SPEED_LSM, lane_mantissa));
+
+		switch (plt) {
+		case PLT_SYM:
+			attr |= FIELD_PREP(USB_SSP_SUBLINK_SPEED_ST,
+					   USB_SSP_SUBLINK_SPEED_ST_SYM_RX);
+			ssp_cap->bmSublinkSpeedAttr[offset++] = cpu_to_le32(attr);
+
+			attr &= ~USB_SSP_SUBLINK_SPEED_ST;
+			attr |= FIELD_PREP(USB_SSP_SUBLINK_SPEED_ST,
+					   USB_SSP_SUBLINK_SPEED_ST_SYM_TX);
+			ssp_cap->bmSublinkSpeedAttr[offset++] = cpu_to_le32(attr);
+			break;
+		case PLT_ASYM_RX:
+			attr |= FIELD_PREP(USB_SSP_SUBLINK_SPEED_ST,
+					   USB_SSP_SUBLINK_SPEED_ST_ASYM_RX);
+			ssp_cap->bmSublinkSpeedAttr[offset++] = cpu_to_le32(attr);
+			break;
+		case PLT_ASYM_TX:
+			attr |= FIELD_PREP(USB_SSP_SUBLINK_SPEED_ST,
+					   USB_SSP_SUBLINK_SPEED_ST_ASYM_TX);
+			ssp_cap->bmSublinkSpeedAttr[offset++] = cpu_to_le32(attr);
+			break;
+		}
+	}
+out:
+	ssp_cap->wFunctionalitySupport =
+		cpu_to_le16(FIELD_PREP(USB_SSP_MIN_SUBLINK_SPEED_ATTRIBUTE_ID,
+				       min_ssid) |
+			    FIELD_PREP(USB_SSP_MIN_RX_LANE_COUNT, 1) |
+			    FIELD_PREP(USB_SSP_MIN_TX_LANE_COUNT, 1));
+
+	return le16_to_cpu(bos->wTotalLength);
+}
+
+static __maybe_unused int xhci_create_usb3_bos_desc(struct xhci_hcd *xhci, char *buf,
 				     u16 wLength)
 {
 	struct xhci_port_cap *port_cap = NULL;

Quoted 196 lines · Thinh Nguyen

The current xhci_create_usb3_bos_desc() uses a static bos u8 array and various magic numbers and offsets making it difficult to extend support for USB 3.2. Let's rewrite this entire function to support dual-lane in USB 3.2.

The hub driver matches the port speed ID from the extended port status to the SSID of the sublink speed attributes to detect if the device supports SuperSpeed Plus. Currently we don't provide the default gen1x2 and gen2x2 sublink speed capability descriptor for USB 3.2 roothub. The USB stack depends on this to detect and match the correct speed. In addition, if the xHCI host provides Protocol Speed ID (PSI) capability, then make sure to convert Protocol Speed ID Mantissa and Exponent (PSIM & PSIE) to lane speed for gen1x2 and gen2x2.

Signed-off-by Thinh Nguyen <[email protected]>

---
Changes in v2:
- Use static array for SSA per Mathias suggestion
- Check bcdUSB >= 0x320 instead of bcdUSB == 0x320 per Mathias suggestion
- When host uses custom PSI, SSIC is the psi_uid_count and not SSAC. I missed this when transferring the previous logic over. Previous implementation was incorrect. Let's fix it here.

 drivers/usb/host/xhci-hub.c | 237 +++++++++++++++++++++++++++++++++++-
 1 file changed, 235 insertions(+), 2 deletions(-)

drivers/usb/host/xhci-hub.c +154 -1

index 74c497fd3476..eddd139c2260 100644
@@ -11,6 +11,7 @@
 
 #include <linux/slab.h>
 #include <asm/unaligned.h>
+#include <linux/bitfield.h>
 
 #include "xhci.h"
 #include "xhci-trace.h"

@@ -52,7 +53,239 @@ static u8 usb_bos_descriptor [] = {
 	0xb5, 0x40, 0x0a, 0x00,		/* 10Gbps, SSP, symmetric, tx, ID = 5 */
 };
 
-static int xhci_create_usb3_bos_desc(struct xhci_hcd *xhci, char *buf,
+/* Default sublink speed attribute of each lane */
+static u32 ssp_cap_default_ssa[] = {
+	0x00050034, /* USB 3.0 SS Gen1x1 id:4 symmetric rx 5Gbps */
+	0x000500b4, /* USB 3.0 SS Gen1x1 id:4 symmetric tx 5Gbps */
+	0x000a4035, /* USB 3.1 SSP Gen2x1 id:5 symmetric rx 10Gbps */
+	0x000a40b5, /* USB 3.1 SSP Gen2x1 id:5 symmetric tx 10Gbps */
+	0x00054036, /* USB 3.2 SSP Gen1x2 id:6 symmetric rx 5Gbps */
+	0x000540b6, /* USB 3.2 SSP Gen1x2 id:6 symmetric tx 5Gbps */
+	0x000a4037, /* USB 3.2 SSP Gen2x2 id:7 symmetric rx 10Gbps */
+	0x000a40b7, /* USB 3.2 SSP Gen2x2 id:7 symmetric tx 10Gbps */
+};
+
+static int xhci_create_usb3x_bos_desc(struct xhci_hcd *xhci, char *buf,
+				      u16 wLength)
+{
+	struct usb_bos_descriptor	*bos;
+	struct usb_ss_cap_descriptor	*ss_cap;
+	struct usb_ssp_cap_descriptor	*ssp_cap;
+	struct xhci_port_cap		*port_cap = NULL;
+	u16				bcdUSB;
+	u32				reg;
+	u32				min_rate = 0;
+	u8				min_ssid;
+	u8				ssac;
+	u8				ssic;
+	int				offset;
+	int				i;
+
+	/* BOS descriptor */
+	bos = (struct usb_bos_descriptor *)buf;
+	bos->bLength = USB_DT_BOS_SIZE;
+	bos->bDescriptorType = USB_DT_BOS;
+	bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE +
+					USB_DT_USB_SS_CAP_SIZE);
+	bos->bNumDeviceCaps = 1;
+
+	/* Create the descriptor for port with the highest revision */
+	for (i = 0; i < xhci->num_port_caps; i++) {
+		u8 major = xhci->port_caps[i].maj_rev;
+		u8 minor = xhci->port_caps[i].min_rev;
+		u16 rev = (major << 8) | minor;
+
+		if (i == 0 || bcdUSB < rev) {
+			bcdUSB = rev;
+			port_cap = &xhci->port_caps[i];
+		}
+	}
+
+	if (bcdUSB >= 0x0310) {
+		if (port_cap->psi_count) {
+			u8 num_sym_ssa = 0;
+
+			for (i = 0; i < port_cap->psi_count; i++) {
+				if ((port_cap->psi[i] & PLT_MASK) == PLT_SYM)
+					num_sym_ssa++;
+			}
+
+			ssac = port_cap->psi_count + num_sym_ssa - 1;
+			ssic = port_cap->psi_uid_count - 1;
+		} else {
+			if (bcdUSB >= 0x0320)
+				ssac = 7;
+			else
+				ssac = 3;
+
+			ssic = (ssac + 1) / 2 - 1;
+		}
+
+		bos->bNumDeviceCaps++;
+		bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE +
+						USB_DT_USB_SS_CAP_SIZE +
+						USB_DT_USB_SSP_CAP_SIZE(ssac));
+	}
+
+	if (wLength < USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE)
+		return wLength;
+
+	/* SuperSpeed USB Device Capability */
+	ss_cap = (struct usb_ss_cap_descriptor *)&buf[USB_DT_BOS_SIZE];
+	ss_cap->bLength = USB_DT_USB_SS_CAP_SIZE;
+	ss_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
+	ss_cap->bDevCapabilityType = USB_SS_CAP_TYPE;
+	ss_cap->bmAttributes = 0; /* set later */
+	ss_cap->wSpeedSupported = cpu_to_le16(USB_5GBPS_OPERATION);
+	ss_cap->bFunctionalitySupport = USB_LOW_SPEED_OPERATION;
+	ss_cap->bU1devExitLat = 0; /* set later */
+	ss_cap->bU2DevExitLat = 0; /* set later */
+
+	reg = readl(&xhci->cap_regs->hcc_params);
+	if (HCC_LTC(reg))
+		ss_cap->bmAttributes |= USB_LTM_SUPPORT;
+
+	if ((xhci->quirks & XHCI_LPM_SUPPORT)) {
+		reg = readl(&xhci->cap_regs->hcs_params3);
+		ss_cap->bU1devExitLat = HCS_U1_LATENCY(reg);
+		ss_cap->bU2DevExitLat = cpu_to_le16(HCS_U2_LATENCY(reg));
+	}
+
+	if (wLength < le16_to_cpu(bos->wTotalLength))
+		return wLength;
+
+	if (bcdUSB < 0x0310)
+		return le16_to_cpu(bos->wTotalLength);
+
+	ssp_cap = (struct usb_ssp_cap_descriptor *)&buf[USB_DT_BOS_SIZE +
+		USB_DT_USB_SS_CAP_SIZE];
+	ssp_cap->bLength = USB_DT_USB_SSP_CAP_SIZE(ssac);
+	ssp_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
+	ssp_cap->bDevCapabilityType = USB_SSP_CAP_TYPE;
+	ssp_cap->bReserved = 0;
+	ssp_cap->wReserved = 0;
+	ssp_cap->bmAttributes =
+		cpu_to_le32(FIELD_PREP(USB_SSP_SUBLINK_SPEED_ATTRIBS, ssac) |
+			    FIELD_PREP(USB_SSP_SUBLINK_SPEED_IDS, ssic));
+
+	if (!port_cap->psi_count) {
+		for (i = 0; i < ssac + 1; i++)
+			ssp_cap->bmSublinkSpeedAttr[i] =
+				cpu_to_le32(ssp_cap_default_ssa[i]);
+
+		min_ssid = 4;
+		goto out;
+	}
+
+	offset = 0;
+	for (i = 0; i < port_cap->psi_count; i++) {
+		u32 psi;
+		u32 attr;
+		u8 ssid;
+		u8 lp;
+		u8 lse;
+		u8 psie;
+		u16 lane_mantissa;
+		u16 psim;
+		u16 plt;
+
+		psi = port_cap->psi[i];
+		ssid = XHCI_EXT_PORT_PSIV(psi);
+		lp = XHCI_EXT_PORT_LP(psi);
+		psie = XHCI_EXT_PORT_PSIE(psi);
+		psim = XHCI_EXT_PORT_PSIM(psi);
+		plt = psi & PLT_MASK;
+
+		lse = psie;
+		lane_mantissa = psim;
+
+		/* Shift to Gbps and set SSP Link Protocol if 10Gpbs */
+		for (; psie < USB_SSP_SUBLINK_SPEED_LSE_GBPS; psie++)
+			psim /= 1000;
+
+		if (!min_rate || psim < min_rate) {
+			min_ssid = ssid;
+			min_rate = psim;

drivers/usb/host/xhci-hub.c static u8 usb_bos_descriptor [] = { · line 213

Quoted 5 lines

drivers/usb/host/xhci-hub.c +5 -0

+		}
+
+		/* Some host controllers don't set the link protocol for SSP */
+		if (psim >= 10)
+			lp = USB_SSP_SUBLINK_SPEED_LP_SSP;

Maybe we should limit the above fix to older than USB 3.2 hosts. xHCI supporting Gen 1x2 can in theory have psim==10 even if it only supports SS link protocol, not SSP.

I'd guess newer USB 3.2 hosts have have fixed the LP bit.

Quoted 20 lines

drivers/usb/host/xhci-hub.c +20 -0

+
+		/*
+		 * PSIM and PSIE represent the total speed of PSI. The BOS
+		 * descriptor SSP sublink speed attribute lane mantissa
+		 * describes the lane speed. E.g. PSIM and PSIE for gen2x2
+		 * is 20Gbps, but the BOS descriptor lane speed mantissa is
+		 * 10Gbps. Check and modify the mantissa value to match the
+		 * lane speed.
+		 */
+		if (bcdUSB == 0x0320 && plt == PLT_SYM) {
+			/*
+			 * The PSI dword for gen1x2 and gen2x1 share the same
+			 * values. But the lane speed for gen1x2 is 5Gbps while
+			 * gen2x1 is 10Gbps. If the previous PSI dword SSID is
+			 * 5 and the PSIE and PSIM match with SSID 6, let's
+			 * assume that the controller follows the default speed
+			 * id with SSID 6 for gen1x2.
+			 */
+			if (ssid == 6 && psie == 3 && psim == 10 && i) {
+				u32 prev = port_cap->psi[i - 1];

drivers/usb/host/xhci-hub.c static u8 usb_bos_descriptor [] = { · line 240

Quoted 7 lines

drivers/usb/host/xhci-hub.c +7 -0

+
+				if ((prev & PLT_MASK) == PLT_SYM &&
+				    XHCI_EXT_PORT_PSIV(prev) == 5 &&
+				    XHCI_EXT_PORT_PSIE(prev) == 3 &&
+				    XHCI_EXT_PORT_PSIM(prev) == 10) {
+					lse = USB_SSP_SUBLINK_SPEED_LSE_GBPS;
+					lane_mantissa = 5;

This is a very specific workaround designed for one default case.

drivers/usb/host/xhci-hub.c static u8 usb_bos_descriptor [] = { · line 247

Quoted 8 lines

drivers/usb/host/xhci-hub.c +7 -0

+				}
+			}
+
+			if (psie == 3 && psim > 10) {
+				lse = USB_SSP_SUBLINK_SPEED_LSE_GBPS;
+				lane_mantissa = 10;
+			}

So is this.

Maybe something more generic could be figured out.
If we assume that bcdUSB >= 0x0320 cases have the Link Protocol (LP) bit is set correctly, we could do something like:

if (bcdUSB >= 0x0320)
if (LP && psim > 10) || (!LP && (psim > 5))
psim = psim / 2 /* divide by lane count */

Not sure if above pseudocode works with SSIC cases

We are also forcing the speeds to Gbps (current code does this as well) This is rounding down non-standard speeds. (SSIC at 2915 Mbps for example)

Quoted 47 lines

drivers/usb/host/xhci-hub.c +41 -0

+		}
+
+		attr = (FIELD_PREP(USB_SSP_SUBLINK_SPEED_SSID, ssid) |
+			FIELD_PREP(USB_SSP_SUBLINK_SPEED_LP, lp) |
+			FIELD_PREP(USB_SSP_SUBLINK_SPEED_LSE, lse) |
+			FIELD_PREP(USB_SSP_SUBLINK_SPEED_LSM, lane_mantissa));
+
+		switch (plt) {
+		case PLT_SYM:
+			attr |= FIELD_PREP(USB_SSP_SUBLINK_SPEED_ST,
+					   USB_SSP_SUBLINK_SPEED_ST_SYM_RX);
+			ssp_cap->bmSublinkSpeedAttr[offset++] = cpu_to_le32(attr);
+
+			attr &= ~USB_SSP_SUBLINK_SPEED_ST;
+			attr |= FIELD_PREP(USB_SSP_SUBLINK_SPEED_ST,
+					   USB_SSP_SUBLINK_SPEED_ST_SYM_TX);
+			ssp_cap->bmSublinkSpeedAttr[offset++] = cpu_to_le32(attr);
+			break;
+		case PLT_ASYM_RX:
+			attr |= FIELD_PREP(USB_SSP_SUBLINK_SPEED_ST,
+					   USB_SSP_SUBLINK_SPEED_ST_ASYM_RX);
+			ssp_cap->bmSublinkSpeedAttr[offset++] = cpu_to_le32(attr);
+			break;
+		case PLT_ASYM_TX:
+			attr |= FIELD_PREP(USB_SSP_SUBLINK_SPEED_ST,
+					   USB_SSP_SUBLINK_SPEED_ST_ASYM_TX);
+			ssp_cap->bmSublinkSpeedAttr[offset++] = cpu_to_le32(attr);
+			break;
+		}
+	}
+out:
+	ssp_cap->wFunctionalitySupport =
+		cpu_to_le16(FIELD_PREP(USB_SSP_MIN_SUBLINK_SPEED_ATTRIBUTE_ID,
+				       min_ssid) |
+			    FIELD_PREP(USB_SSP_MIN_RX_LANE_COUNT, 1) |
+			    FIELD_PREP(USB_SSP_MIN_TX_LANE_COUNT, 1));
+
+	return le16_to_cpu(bos->wTotalLength);
+}
+
+static __maybe_unused int xhci_create_usb3_bos_desc(struct xhci_hcd *xhci, char *buf,
 				     u16 wLength)
 {
 	struct xhci_port_cap *port_cap = NULL;

drivers/usb/host/xhci-hub.c int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, · line 1376

Quoted 8 lines

drivers/usb/host/xhci-hub.c +1 -1

@@ -1137,7 +1370,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 		if (hcd->speed < HCD_USB3)
 			goto error;
 
-		retval = xhci_create_usb3_bos_desc(xhci, buf, wLength);
+		retval = xhci_create_usb3x_bos_desc(xhci, buf, wLength);
 		spin_unlock_irqrestore(&xhci->lock, flags);
 		return retval;
 	case GetPortStatus:

This is anyways a lot better than what we currently have.
Would be nice to get those xHCI PSIM values nicely converted to USB 3.x bmSuperSpeedAttr Lane Speed Mantissa.

Otherwise everyting looks good

Quoted 197 lines · Mathias Nyman

Quoted 196 lines · Thinh Nguyen

The current xhci_create_usb3_bos_desc() uses a static bos u8 array and various magic numbers and offsets making it difficult to extend support for USB 3.2. Let's rewrite this entire function to support dual-lane in USB 3.2.

The hub driver matches the port speed ID from the extended port status to the SSID of the sublink speed attributes to detect if the device supports SuperSpeed Plus. Currently we don't provide the default gen1x2 and gen2x2 sublink speed capability descriptor for USB 3.2 roothub. The USB stack depends on this to detect and match the correct speed. In addition, if the xHCI host provides Protocol Speed ID (PSI) capability, then make sure to convert Protocol Speed ID Mantissa and Exponent (PSIM & PSIE) to lane speed for gen1x2 and gen2x2.

Signed-off-by Thinh Nguyen <[email protected]>

---
Changes in v2:
- Use static array for SSA per Mathias suggestion
- Check bcdUSB >= 0x320 instead of bcdUSB == 0x320 per Mathias suggestion
- When host uses custom PSI, SSIC is the psi_uid_count and not SSAC. I missed this when transferring the previous logic over. Previous implementation was incorrect. Let's fix it here.

 drivers/usb/host/xhci-hub.c | 237 +++++++++++++++++++++++++++++++++++-
 1 file changed, 235 insertions(+), 2 deletions(-)

drivers/usb/host/xhci-hub.c +154 -1

index 74c497fd3476..eddd139c2260 100644
@@ -11,6 +11,7 @@
 
 #include <linux/slab.h>
 #include <asm/unaligned.h>
+#include <linux/bitfield.h>
 
 #include "xhci.h"
 #include "xhci-trace.h"

@@ -52,7 +53,239 @@ static u8 usb_bos_descriptor [] = {
 	0xb5, 0x40, 0x0a, 0x00,		/* 10Gbps, SSP, symmetric, tx, ID = 5 */
 };
 
-static int xhci_create_usb3_bos_desc(struct xhci_hcd *xhci, char *buf,
+/* Default sublink speed attribute of each lane */
+static u32 ssp_cap_default_ssa[] = {
+	0x00050034, /* USB 3.0 SS Gen1x1 id:4 symmetric rx 5Gbps */
+	0x000500b4, /* USB 3.0 SS Gen1x1 id:4 symmetric tx 5Gbps */
+	0x000a4035, /* USB 3.1 SSP Gen2x1 id:5 symmetric rx 10Gbps */
+	0x000a40b5, /* USB 3.1 SSP Gen2x1 id:5 symmetric tx 10Gbps */
+	0x00054036, /* USB 3.2 SSP Gen1x2 id:6 symmetric rx 5Gbps */
+	0x000540b6, /* USB 3.2 SSP Gen1x2 id:6 symmetric tx 5Gbps */
+	0x000a4037, /* USB 3.2 SSP Gen2x2 id:7 symmetric rx 10Gbps */
+	0x000a40b7, /* USB 3.2 SSP Gen2x2 id:7 symmetric tx 10Gbps */
+};
+
+static int xhci_create_usb3x_bos_desc(struct xhci_hcd *xhci, char *buf,
+				      u16 wLength)
+{
+	struct usb_bos_descriptor	*bos;
+	struct usb_ss_cap_descriptor	*ss_cap;
+	struct usb_ssp_cap_descriptor	*ssp_cap;
+	struct xhci_port_cap		*port_cap = NULL;
+	u16				bcdUSB;
+	u32				reg;
+	u32				min_rate = 0;
+	u8				min_ssid;
+	u8				ssac;
+	u8				ssic;
+	int				offset;
+	int				i;
+
+	/* BOS descriptor */
+	bos = (struct usb_bos_descriptor *)buf;
+	bos->bLength = USB_DT_BOS_SIZE;
+	bos->bDescriptorType = USB_DT_BOS;
+	bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE +
+					USB_DT_USB_SS_CAP_SIZE);
+	bos->bNumDeviceCaps = 1;
+
+	/* Create the descriptor for port with the highest revision */
+	for (i = 0; i < xhci->num_port_caps; i++) {
+		u8 major = xhci->port_caps[i].maj_rev;
+		u8 minor = xhci->port_caps[i].min_rev;
+		u16 rev = (major << 8) | minor;
+
+		if (i == 0 || bcdUSB < rev) {
+			bcdUSB = rev;
+			port_cap = &xhci->port_caps[i];
+		}
+	}
+
+	if (bcdUSB >= 0x0310) {
+		if (port_cap->psi_count) {
+			u8 num_sym_ssa = 0;
+
+			for (i = 0; i < port_cap->psi_count; i++) {
+				if ((port_cap->psi[i] & PLT_MASK) == PLT_SYM)
+					num_sym_ssa++;
+			}
+
+			ssac = port_cap->psi_count + num_sym_ssa - 1;
+			ssic = port_cap->psi_uid_count - 1;
+		} else {
+			if (bcdUSB >= 0x0320)
+				ssac = 7;
+			else
+				ssac = 3;
+
+			ssic = (ssac + 1) / 2 - 1;
+		}
+
+		bos->bNumDeviceCaps++;
+		bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE +
+						USB_DT_USB_SS_CAP_SIZE +
+						USB_DT_USB_SSP_CAP_SIZE(ssac));
+	}
+
+	if (wLength < USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE)
+		return wLength;
+
+	/* SuperSpeed USB Device Capability */
+	ss_cap = (struct usb_ss_cap_descriptor *)&buf[USB_DT_BOS_SIZE];
+	ss_cap->bLength = USB_DT_USB_SS_CAP_SIZE;
+	ss_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
+	ss_cap->bDevCapabilityType = USB_SS_CAP_TYPE;
+	ss_cap->bmAttributes = 0; /* set later */
+	ss_cap->wSpeedSupported = cpu_to_le16(USB_5GBPS_OPERATION);
+	ss_cap->bFunctionalitySupport = USB_LOW_SPEED_OPERATION;
+	ss_cap->bU1devExitLat = 0; /* set later */
+	ss_cap->bU2DevExitLat = 0; /* set later */
+
+	reg = readl(&xhci->cap_regs->hcc_params);
+	if (HCC_LTC(reg))
+		ss_cap->bmAttributes |= USB_LTM_SUPPORT;
+
+	if ((xhci->quirks & XHCI_LPM_SUPPORT)) {
+		reg = readl(&xhci->cap_regs->hcs_params3);
+		ss_cap->bU1devExitLat = HCS_U1_LATENCY(reg);
+		ss_cap->bU2DevExitLat = cpu_to_le16(HCS_U2_LATENCY(reg));
+	}
+
+	if (wLength < le16_to_cpu(bos->wTotalLength))
+		return wLength;
+
+	if (bcdUSB < 0x0310)
+		return le16_to_cpu(bos->wTotalLength);
+
+	ssp_cap = (struct usb_ssp_cap_descriptor *)&buf[USB_DT_BOS_SIZE +
+		USB_DT_USB_SS_CAP_SIZE];
+	ssp_cap->bLength = USB_DT_USB_SSP_CAP_SIZE(ssac);
+	ssp_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
+	ssp_cap->bDevCapabilityType = USB_SSP_CAP_TYPE;
+	ssp_cap->bReserved = 0;
+	ssp_cap->wReserved = 0;
+	ssp_cap->bmAttributes =
+		cpu_to_le32(FIELD_PREP(USB_SSP_SUBLINK_SPEED_ATTRIBS, ssac) |
+			    FIELD_PREP(USB_SSP_SUBLINK_SPEED_IDS, ssic));
+
+	if (!port_cap->psi_count) {
+		for (i = 0; i < ssac + 1; i++)
+			ssp_cap->bmSublinkSpeedAttr[i] =
+				cpu_to_le32(ssp_cap_default_ssa[i]);
+
+		min_ssid = 4;
+		goto out;
+	}
+
+	offset = 0;
+	for (i = 0; i < port_cap->psi_count; i++) {
+		u32 psi;
+		u32 attr;
+		u8 ssid;
+		u8 lp;
+		u8 lse;
+		u8 psie;
+		u16 lane_mantissa;
+		u16 psim;
+		u16 plt;
+
+		psi = port_cap->psi[i];
+		ssid = XHCI_EXT_PORT_PSIV(psi);
+		lp = XHCI_EXT_PORT_LP(psi);
+		psie = XHCI_EXT_PORT_PSIE(psi);
+		psim = XHCI_EXT_PORT_PSIM(psi);
+		plt = psi & PLT_MASK;
+
+		lse = psie;
+		lane_mantissa = psim;
+
+		/* Shift to Gbps and set SSP Link Protocol if 10Gpbs */
+		for (; psie < USB_SSP_SUBLINK_SPEED_LSE_GBPS; psie++)
+			psim /= 1000;
+
+		if (!min_rate || psim < min_rate) {
+			min_ssid = ssid;
+			min_rate = psim;

Quoted 8 lines

drivers/usb/host/xhci-hub.c static u8 usb_bos_descriptor [] = { · line 213

Quoted 5 lines

drivers/usb/host/xhci-hub.c +5 -0

+		}
+
+		/* Some host controllers don't set the link protocol for SSP */
+		if (psim >= 10)
+			lp = USB_SSP_SUBLINK_SPEED_LP_SSP;

Maybe we should limit the above fix to older than USB 3.2 hosts. xHCI supporting Gen 1x2 can in theory have psim==10 even if it only supports SS link protocol, not SSP.

Gen 1x2 uses SuperSpeed Plus link protocol. See USB 3.2 spec section 3.2