xhci: Add new short TX quirk for Fresco Logic host. (1530bbc6) · Commits · 戴 / test

Sergio reported that when he recorded audio from a USB headset mic plugged into the USB 3.0 port on his ASUS N53SV-DH72, the audio sounded "robotic". When plugged into the USB 2.0 port under EHCI on the same laptop, the audio sounded fine. The device is: Bus 002 Device 004: ID 046d:0a0c Logitech, Inc. Clear Chat Comfort USB Headset The problem was tracked down to the Fresco Logic xHCI host controller not correctly reporting short transfers on isochronous IN endpoints. The driver would submit a 96 byte transfer, the device would only send 88 or 90 bytes, and the xHCI host would report the transfer had a "successful" completion code, with an untransferred buffer length of 8 or 6 bytes. The successful completion code and non-zero untransferred length is a contradiction. The xHCI host is supposed to only mark a transfer as successful if all the bytes are transferred. Otherwise, the transfer should be marked with a short packet completion code. Without the EHCI bus trace, we wouldn't know whether the xHCI driver should trust the completion code or the untransferred length. With it, we know to trust the untransferred length. Add a new xHCI quirk for the Fresco Logic host controller. If a transfer is reported as successful, but the untransferred length is non-zero, print a warning. For the Fresco Logic host, change the completion code to COMP_SHORT_TX and process the transfer like a short transfer. This should be backported to stable kernels that contain the commit "xhci: Disable MSI for some Fresco Logic hosts." That commit was marked for stable kernels as old as 2.6.36. Signed-off-by:

Sarah Sharp <sarah.a.sharp@linux.intel.com> Reported-by:

Sergio Correia <lists@uece.net> Tested-by:

Sergio Correia <lists@uece.net> Cc: stable@vger.kernel.org Signed-off-by:

Sarah Sharp <sarah.a.sharp@linux.intel.com>

drivers/usb/host/xhci-pci.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -72,6 +72,7 @@ static void xhci_pci_quirks(struct device dev, struct xhci_hcd xhci)
		xhci_dbg(xhci, "QUIRK: Fresco Logic revision %u "
		"has broken MSI implementation\n",
		pdev->revision);
		xhci->quirks \|= XHCI_TRUST_TX_LENGTH;
		}

		if (pdev->vendor == PCI_VENDOR_ID_NEC)

drivers/usb/host/xhci-ring.c

+17 −3

Original line number	Diff line number	Diff line
		@@ -1787,8 +1787,12 @@ static int process_isoc_td(struct xhci_hcd xhci, struct xhci_td td,
		/* handle completion code */
		switch (trb_comp_code) {
		case COMP_SUCCESS:
		if (TRB_LEN(le32_to_cpu(event->transfer_len)) == 0) {
		frame->status = 0;
		break;
		}
		if ((xhci->quirks & XHCI_TRUST_TX_LENGTH))
		trb_comp_code = COMP_SHORT_TX;
		case COMP_SHORT_TX:
		frame->status = td->urb->transfer_flags & URB_SHORT_NOT_OK ?
		-EREMOTEIO : 0;
		@@ -1885,13 +1889,16 @@ static int process_bulk_intr_td(struct xhci_hcd xhci, struct xhci_td td,
		switch (trb_comp_code) {
		case COMP_SUCCESS:
		/* Double check that the HW transferred everything. */
		if (event_trb != td->last_trb) {
		if (event_trb != td->last_trb \|\|
		TRB_LEN(le32_to_cpu(event->transfer_len)) != 0) {
		xhci_warn(xhci, "WARN Successful completion "
		"on short TX\n");
		if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
		*status = -EREMOTEIO;
		else
		*status = 0;
		if ((xhci->quirks & XHCI_TRUST_TX_LENGTH))
		trb_comp_code = COMP_SHORT_TX;
		} else {
		*status = 0;
		}
		@@ -2050,6 +2057,13 @@ static int handle_tx_event(struct xhci_hcd *xhci,
		* transfer type
		*/
		case COMP_SUCCESS:
		if (TRB_LEN(le32_to_cpu(event->transfer_len)) == 0)
		break;
		if (xhci->quirks & XHCI_TRUST_TX_LENGTH)
		trb_comp_code = COMP_SHORT_TX;
		else
		xhci_warn(xhci, "WARN Successful completion on short TX: "
		"needs XHCI_TRUST_TX_LENGTH quirk?\n");
		case COMP_SHORT_TX:
		break;
		case COMP_STOP:

drivers/usb/host/xhci.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -1481,6 +1481,7 @@ struct xhci_hcd {
		#define XHCI_RESET_ON_RESUME (1 << 7)
		#define XHCI_SW_BW_CHECKING (1 << 8)
		#define XHCI_AMD_0x96_HOST (1 << 9)
		#define XHCI_TRUST_TX_LENGTH (1 << 10)
		unsigned int num_active_eps;
		unsigned int limit_active_eps;
		/* There are two roothubs to keep track of bus suspend info for */

Admin message