From: Wesley Cheng quic_wcheng@quicinc.com
[ Upstream commit 6add6dd345cb754ce18ff992c7264cabf31e59f6 ]
There is a 120ms delay implemented for allowing the XHCI host controller to detect a U3 wakeup pulse. The intention is to wait for the device to retry the wakeup event if the USB3 PORTSC doesn't reflect the RESUME link status by the time it is checked. As per the USB3 specification:
tU3WakeupRetryDelay ("Table 7-12. LTSSM State Transition Timeouts")
This would allow the XHCI resume sequence to determine if the root hub needs to be also resumed. However, in case there is no device connected, or if there is only a HSUSB device connected, this delay would still affect the overall resume timing.
Since this delay is solely for detecting U3 wake events (USB3 specific) then ignore this delay for the disconnected case and the HSUSB connected only case.
[skip helper function, rename usb3_connected variable -Mathias ]
Signed-off-by: Wesley Cheng quic_wcheng@quicinc.com Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Link: https://lore.kernel.org/r/20231019102924.2797346-20-mathias.nyman@linux.inte... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/host/xhci.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index e1b1b64a07232..132b76fa7ca60 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -968,6 +968,7 @@ int xhci_resume(struct xhci_hcd *xhci, pm_message_t msg) int retval = 0; bool comp_timer_running = false; bool pending_portevent = false; + bool suspended_usb3_devs = false; bool reinit_xhc = false;
if (!hcd->state) @@ -1115,10 +1116,17 @@ int xhci_resume(struct xhci_hcd *xhci, pm_message_t msg) /* * Resume roothubs only if there are pending events. * USB 3 devices resend U3 LFPS wake after a 100ms delay if - * the first wake signalling failed, give it that chance. + * the first wake signalling failed, give it that chance if + * there are suspended USB 3 devices. */ + if (xhci->usb3_rhub.bus_state.suspended_ports || + xhci->usb3_rhub.bus_state.bus_suspended) + suspended_usb3_devs = true; + pending_portevent = xhci_pending_portevent(xhci); - if (!pending_portevent && msg.event == PM_EVENT_AUTO_RESUME) { + + if (suspended_usb3_devs && !pending_portevent && + msg.event == PM_EVENT_AUTO_RESUME) { msleep(120); pending_portevent = xhci_pending_portevent(xhci); }