From 346e99736c3ce328fd42d678343b70243aca5f36 Mon Sep 17 00:00:00 2001 From: Mathias Nyman Date: Thu, 20 Oct 2016 18:09:19 +0300 Subject: [PATCH] xhci: workaround for hosts missing CAS bit If a device is unplugged and replugged during Sx system suspend some Intel xHC hosts will overwrite the CAS (Cold attach status) flag and no device connection is noticed in resume. A device in this state can be identified in resume if its link state is in polling or compliance mode, and the current connect status is 0. A device in this state needs to be warm reset. Intel 100/c230 series PCH specification update Doc #332692-006 Errata #8 Observed on Cherryview and Apollolake as they go into compliance mode if LFPS times out during polling, and re-plugged devices are not discovered at resume. Signed-off-by: Mathias Nyman CC: Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-hub.c | 37 +++++++++++++++++++++++++++++++++++++ drivers/usb/host/xhci-pci.c | 6 ++++++ drivers/usb/host/xhci.h | 3 +++ 3 files changed, 46 insertions(+) diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index 730b9fd..c047362 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -1355,6 +1355,35 @@ int xhci_bus_suspend(struct usb_hcd *hcd) return 0; } +/* + * Workaround for missing Cold Attach Status (CAS) if device re-plugged in S3. + * warm reset a USB3 device stuck in polling or compliance mode after resume. + * See Intel 100/c230 series PCH specification update Doc #332692-006 Errata #8 + */ +static bool xhci_port_missing_cas_quirk(int port_index, + __le32 __iomem **port_array) +{ + u32 portsc; + + portsc = readl(port_array[port_index]); + + /* if any of these are set we are not stuck */ + if (portsc & (PORT_CONNECT | PORT_CAS)) + return false; + + if (((portsc & PORT_PLS_MASK) != XDEV_POLLING) && + ((portsc & PORT_PLS_MASK) != XDEV_COMP_MODE)) + return false; + + /* clear wakeup/change bits, and do a warm port reset */ + portsc &= ~(PORT_RWC_BITS | PORT_CEC | PORT_WAKE_BITS); + portsc |= PORT_WR; + writel(portsc, port_array[port_index]); + /* flush write */ + readl(port_array[port_index]); + return true; +} + int xhci_bus_resume(struct usb_hcd *hcd) { struct xhci_hcd *xhci = hcd_to_xhci(hcd); @@ -1392,6 +1421,14 @@ int xhci_bus_resume(struct usb_hcd *hcd) u32 temp; temp = readl(port_array[port_index]); + + /* warm reset CAS limited ports stuck in polling/compliance */ + if ((xhci->quirks & XHCI_MISSING_CAS) && + (hcd->speed >= HCD_USB3) && + xhci_port_missing_cas_quirk(port_index, port_array)) { + xhci_dbg(xhci, "reset stuck port %d\n", port_index); + continue; + } if (DEV_SUPERSPEED_ANY(temp)) temp &= ~(PORT_RWC_BITS | PORT_CEC | PORT_WAKE_BITS); else diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index 314179b..e96ae80 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -51,6 +51,7 @@ #define PCI_DEVICE_ID_INTEL_SUNRISEPOINT_LP_XHCI 0x9d2f #define PCI_DEVICE_ID_INTEL_BROXTON_M_XHCI 0x0aa8 #define PCI_DEVICE_ID_INTEL_BROXTON_B_XHCI 0x1aa8 +#define PCI_DEVICE_ID_INTEL_APL_XHCI 0x5aa8 static const char hcd_name[] = "xhci_hcd"; @@ -171,6 +172,11 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci) pdev->device == PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI) { xhci->quirks |= XHCI_SSIC_PORT_UNUSED; } + if (pdev->vendor == PCI_VENDOR_ID_INTEL && + (pdev->device == PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI || + pdev->device == PCI_DEVICE_ID_INTEL_APL_XHCI)) + xhci->quirks |= XHCI_MISSING_CAS; + if (pdev->vendor == PCI_VENDOR_ID_ETRON && pdev->device == PCI_DEVICE_ID_EJ168) { xhci->quirks |= XHCI_RESET_ON_RESUME; diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index b2c1dc5..f945380 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -314,6 +314,8 @@ struct xhci_op_regs { #define XDEV_U2 (0x2 << 5) #define XDEV_U3 (0x3 << 5) #define XDEV_INACTIVE (0x6 << 5) +#define XDEV_POLLING (0x7 << 5) +#define XDEV_COMP_MODE (0xa << 5) #define XDEV_RESUME (0xf << 5) /* true: port has power (see HCC_PPC) */ #define PORT_POWER (1 << 9) @@ -1653,6 +1655,7 @@ struct xhci_hcd { #define XHCI_MTK_HOST (1 << 21) #define XHCI_SSIC_PORT_UNUSED (1 << 22) #define XHCI_NO_64BIT_SUPPORT (1 << 23) +#define XHCI_MISSING_CAS (1 << 24) unsigned int num_active_eps; unsigned int limit_active_eps; /* There are two roothubs to keep track of bus suspend info for */ -- 2.7.4