From 96908589a8b2584b1185f834d365f5cc360e8226 Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Wed, 27 Aug 2014 16:38:04 -0500 Subject: [PATCH] usb: host: xhci: fix compliance mode workaround Commit 71c731a (usb: host: xhci: Fix Compliance Mode on SN65LVP3502CP Hardware) implemented a workaround for a known issue with Texas Instruments' USB 3.0 redriver IC but it left a condition where any xHCI host would be taken out of reset if port was placed in compliance mode and there was no device connected to the port. That condition would trigger a fake connection to a non-existent device so that usbcore would trigger a warm reset of the port, thus taking the link out of reset. This has the side-effect of preventing any xHCI host connected to a Linux machine from starting and running the USB 3.0 Electrical Compliance Suite because the port will mysteriously taken out of compliance mode and, thus, xHCI won't step through the necessary compliance patterns for link validation. This patch fixes the issue by just adding a missing check for XHCI_COMP_MODE_QUIRK inside xhci_hub_report_usb3_link_state() when PORT_CAS isn't set. This patch should be backported to all kernels containing commit 71c731a. Fixes: 71c731a (usb: host: xhci: Fix Compliance Mode on SN65LVP3502CP Hardware) Cc: Alexis R. Cortes Cc: # v3.2+ Signed-off-by: Felipe Balbi Acked-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-hub.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index aa79e8749040..69aece31143a 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -468,7 +468,8 @@ static void xhci_hub_report_usb2_link_state(u32 *status, u32 status_reg) } /* Updates Link Status for super Speed port */ -static void xhci_hub_report_usb3_link_state(u32 *status, u32 status_reg) +static void xhci_hub_report_usb3_link_state(struct xhci_hcd *xhci, + u32 *status, u32 status_reg) { u32 pls = status_reg & PORT_PLS_MASK; @@ -507,7 +508,8 @@ static void xhci_hub_report_usb3_link_state(u32 *status, u32 status_reg) * in which sometimes the port enters compliance mode * caused by a delay on the host-device negotiation. */ - if (pls == USB_SS_PORT_LS_COMP_MOD) + if ((xhci->quirks & XHCI_COMP_MODE_QUIRK) && + (pls == USB_SS_PORT_LS_COMP_MOD)) pls |= USB_PORT_STAT_CONNECTION; } @@ -666,7 +668,7 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd, } /* Update Port Link State */ if (hcd->speed == HCD_USB3) { - xhci_hub_report_usb3_link_state(&status, raw_port_status); + xhci_hub_report_usb3_link_state(xhci, &status, raw_port_status); /* * Verify if all USB3 Ports Have entered U0 already. * Delete Compliance Mode Timer if so. -- 2.20.1