patch "xhci: set missing SuperSpeedPlus Link Protocol bit in roothub" added to usb-linus

This is a note to let you know that I've just added the patch titled

xhci: set missing SuperSpeedPlus Link Protocol bit in roothub

to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From: Mathias Nyman <[email protected]>
Date: Mon, 18 Sep 2017 17:39:18 +0300
Subject: xhci: set missing SuperSpeedPlus Link Protocol bit in roothub
descriptor

A SuperSpeedPlus roothub needs to have the Link Protocol (LP) bit set in the bmSublinkSpeedAttr[] entry of a SuperSpeedPlus descriptor.

If the xhci controller has an optional Protocol Speed ID (PSI) table then that will be used as a base to create the roothub SuperSpeedPlus descriptor.
The PSI table does not however necessary contain the LP bit so we need to set it manually.

Check the psi speed and set LP bit if speed is 10Gbps or higher. We're not setting it for 5 to 10Gbps as USB 3.1 specification always mention SuperSpeedPlus for 10Gbps or higher, and some SSIC USB 3.0 speeds can be over 5Gbps, such as SSIC-G3B-L1 at 5830 Mbps

---
 drivers/usb/host/xhci-hub.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

index ad89a6d4111b..4dba2cf73cbe 100644
@@ -112,7 +112,7 @@ static int xhci_create_usb3_bos_desc(struct xhci_hcd *xhci, char *buf,
 
 	/* If PSI table exists, add the custom speed attributes from it */
 	if (usb3_1 && xhci->usb3_rhub.psi_count) {
-		u32 ssp_cap_base, bm_attrib, psi;
+		u32 ssp_cap_base, bm_attrib, psi, psi_mant, psi_exp;
 		int offset;
 
 		ssp_cap_base = USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE;

@@ -139,6 +139,15 @@ static int xhci_create_usb3_bos_desc(struct xhci_hcd *xhci, char *buf,
 		for (i = 0; i < xhci->usb3_rhub.psi_count; i++) {
 			psi = xhci->usb3_rhub.psi[i];
 			psi &= ~USB_SSP_SUBLINK_SPEED_RSVD;
+			psi_exp = XHCI_EXT_PORT_PSIE(psi);
+			psi_mant = XHCI_EXT_PORT_PSIM(psi);
+
+			/* Shift to Gbps and set SSP Link BIT(14) if 10Gpbs */
+			for (; psi_exp < 3; psi_exp++)
+				psi_mant /= 1000;
+			if (psi_mant >= 10)
+				psi |= BIT(14);
+
 			if ((psi & PLT_MASK) == PLT_SYM) {
 			/* Symmetric, create SSA RX and TX from one PSI entry */
 				put_unaligned_le32(psi, &buf[offset]);

2.14.1