From 1530bbc6272d9da1e39ef8e06190d42c13a02733 Mon Sep 17 00:00:00 2001 From: Sarah Sharp Date: Tue, 8 May 2012 09:22:49 -0700 Subject: xhci: Add new short TX quirk for Fresco Logic host. 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 f5182b4155b9d686c5540a6822486400e34ddd98 "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 Reported-by: Sergio Correia Tested-by: Sergio Correia Cc: stable@vger.kernel.org Signed-off-by: Sarah Sharp --- drivers/usb/host/xhci-pci.c | 1 + drivers/usb/host/xhci-ring.c | 20 +++++++++++++++++--- drivers/usb/host/xhci.h | 1 + 3 files changed, 19 insertions(+), 3 deletions(-) (limited to 'drivers/usb/host') diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index 7a856a767e7..19e89216436 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -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) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 329fd2a98dd..c60617bb8c2 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -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: - frame->status = 0; - break; + 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: diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index ce1edd7246a..ac142760fd3 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -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 */ -- cgit v1.2.3-70-g09d2