From: Kai-Heng Feng kai.heng.feng@canonical.com
[ Upstream commit 0200b9f790b0fc9e9a42f685f5ad54b23fe959f4 ]
Like U3 case, xHCI spec doesn't specify the upper bound of U0 transition time. The 20ms is not enough for some devices.
Intead of polling PLS or PLC, we can facilitate the port change event to know that the link transits to U0 is completed.
While at it, also separate U0 and U3 case to make the code cleaner.
[variable rename to u3exit, and skip completion for usb2 ports -Mathias ] Signed-off-by: Kai-Heng Feng kai.heng.feng@canonical.com Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Link: https://lore.kernel.org/r/20200312144517.1593-8-mathias.nyman@linux.intel.co... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/host/xhci-hub.c | 44 +++++++++++++++++++++++++----------- drivers/usb/host/xhci-mem.c | 1 + drivers/usb/host/xhci-ring.c | 1 + drivers/usb/host/xhci.h | 1 + 4 files changed, 34 insertions(+), 13 deletions(-)
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index 712cd44f05ace..02f52d4f74df8 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -1306,7 +1306,33 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, wIndex, link_state); goto error; } + + if (link_state == USB_SS_PORT_LS_U0) { + if ((temp & PORT_PLS_MASK) == XDEV_U0) + break; + + if (!((temp & PORT_PLS_MASK) == XDEV_U1 || + (temp & PORT_PLS_MASK) == XDEV_U2 || + (temp & PORT_PLS_MASK) == XDEV_U3)) { + xhci_warn(xhci, "Can only set port %d to U0 from U state\n", + wIndex); + goto error; + } + reinit_completion(&bus_state->u3exit_done[wIndex]); + xhci_set_link_state(xhci, ports[wIndex], + USB_SS_PORT_LS_U0); + spin_unlock_irqrestore(&xhci->lock, flags); + if (!wait_for_completion_timeout(&bus_state->u3exit_done[wIndex], + msecs_to_jiffies(100))) + xhci_dbg(xhci, "missing U0 port change event for port %d\n", + wIndex); + spin_lock_irqsave(&xhci->lock, flags); + temp = readl(ports[wIndex]->addr); + break; + } + if (link_state == USB_SS_PORT_LS_U3) { + int retries = 16; slot_id = xhci_find_slot_id_by_port(hcd, xhci, wIndex + 1); if (slot_id) { @@ -1317,26 +1343,18 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, xhci_stop_device(xhci, slot_id, 1); spin_lock_irqsave(&xhci->lock, flags); } - } - - xhci_set_link_state(xhci, ports[wIndex], link_state); - - spin_unlock_irqrestore(&xhci->lock, flags); - if (link_state == USB_SS_PORT_LS_U3) { - int retries = 16; - + xhci_set_link_state(xhci, ports[wIndex], USB_SS_PORT_LS_U3); + spin_unlock_irqrestore(&xhci->lock, flags); while (retries--) { usleep_range(4000, 8000); temp = readl(ports[wIndex]->addr); if ((temp & PORT_PLS_MASK) == XDEV_U3) break; } - } - spin_lock_irqsave(&xhci->lock, flags); - - temp = readl(ports[wIndex]->addr); - if (link_state == USB_SS_PORT_LS_U3) + spin_lock_irqsave(&xhci->lock, flags); + temp = readl(ports[wIndex]->addr); bus_state->suspended_ports |= 1 << wIndex; + } break; case USB_PORT_FEAT_POWER: /* diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index 884c601bfa15f..9764122c9cdf2 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -2552,6 +2552,7 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags) xhci->usb3_rhub.bus_state.resume_done[i] = 0; /* Only the USB 2.0 completions will ever be used. */ init_completion(&xhci->usb2_rhub.bus_state.rexit_done[i]); + init_completion(&xhci->usb3_rhub.bus_state.u3exit_done[i]); }
if (scratchpad_alloc(xhci, flags)) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index d23f7408c81f1..c1e63af88356c 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1677,6 +1677,7 @@ static void handle_port_status(struct xhci_hcd *xhci, (portsc & PORT_PLS_MASK) == XDEV_U1 || (portsc & PORT_PLS_MASK) == XDEV_U2)) { xhci_dbg(xhci, "resume SS port %d finished\n", port_id); + complete(&bus_state->u3exit_done[hcd_portnum]); /* We've just brought the device into U0/1/2 through either the * Resume state after a device remote wakeup, or through the * U3Exit state after a host-initiated resume. If it's a device diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 3ecee10fdcdc7..fb1ab63b5fe25 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1694,6 +1694,7 @@ struct xhci_bus_state { /* Which ports are waiting on RExit to U0 transition. */ unsigned long rexit_ports; struct completion rexit_done[USB_MAXCHILDREN]; + struct completion u3exit_done[USB_MAXCHILDREN]; };