From 0200b9f790b0fc9e9a42f685f5ad54b23fe959f4 Mon Sep 17 00:00:00 2001 From: Kai-Heng Feng Date: Thu, 12 Mar 2020 16:45:15 +0200 Subject: xhci: Wait until link state trainsits to U0 after setting USB_SS_PORT_LS_U0 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 Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20200312144517.1593-8-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-hub.c | 44 +++++++++++++++++++++++++++++++------------- 1 file changed, 31 insertions(+), 13 deletions(-) (limited to 'drivers/usb/host/xhci-hub.c') diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index dde46d1d5f6f..af99d2509f16 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -1308,7 +1308,33 @@ 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) { @@ -1319,26 +1345,18 @@ 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: /* -- cgit v1.2.3