We are facing issue while performing the system resume operation from STR where XHCI is going to indefinite hang/sleep state due to wait_for_completion API called in function xhci_alloc_dev for command TRB_ENABLE_SLOT which never completes. Now, xhci_handle_command_timeout function is called and prints "Command timeout" message but never calls complete API for above TRB_ENABLE_SLOT command as xhci_abort_cmd_ring is successful. Solution to above problem is: 1. calling xhci_cleanup_command_queue API even if xhci_abort_cmd_ring is successful or not. 2. checking the status of reset_device in usb core code. Before Fix: root@phoenix:~# echo mem > /sys/power/state PM: Syncing filesystems ... done. Freezing user space processes ... (elapsed 0.001 seconds) done. Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. PM: suspend of devices complete after 103.144 msecs PM: late suspend of devices complete after 1.503 msecs PM: noirq suspend of devices complete after 1.220 msecs Disabling non-boot CPUs ... CPU1: shutdown Retrying again to check for CPU kill CPU1 killed. Enabling non-boot CPUs ... CPU1 is up PM: noirq resume of devices complete after 1.996 msecs PM: early resume of devices complete after 1.152 msecs usb usb1: root hub lost power or was reset usb usb2: root hub lost power or was reset ----- <<hangs indefinitely>> -------------- After Fix: root@phoenix:~# echo mem > /sys/power/state PM: Syncing filesystems ... done. Freezing user space processes ... (elapsed 0.001 seconds) done. Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. PM: suspend of devices complete after 103.086 msecs PM: late suspend of devices complete after 1.517 msecs PM: noirq suspend of devices complete after 1.217 msecs Disabling non-boot CPUs ... CPU1: shutdown Retrying again to check for CPU kill CPU1 killed. Enabling non-boot CPUs ... CPU1 is up PM: noirq resume of devices complete after 1.991 msecs PM: early resume of devices complete after 1.239 msecs usb usb1: root hub lost power or was reset usb usb2: root hub lost power or was reset xhci-hcd xhci-hcd.0.auto: Error while assigning device slot ID xhci-hcd xhci-hcd.0.auto: Max number of devices this xHCI host supports is 127. xhci-hcd xhci-hcd.0.auto: Error while assigning device slot ID xhci-hcd xhci-hcd.0.auto: Max number of devices this xHCI host supports is 127. xhci-hcd xhci-hcd.0.auto: Error while assigning device slot ID xhci-hcd xhci-hcd.0.auto: Max number of devices this xHCI host supports is 127. xhci-hcd xhci-hcd.0.auto: Error while assigning device slot ID xhci-hcd xhci-hcd.0.auto: Max number of devices this xHCI host supports is 127. xhci-hcd xhci-hcd.0.auto: Error while assigning device slot ID xhci-hcd xhci-hcd.0.auto: Max number of devices this xHCI host supports is 127. xhci-hcd xhci-hcd.0.auto: Error while assigning device slot ID xhci-hcd xhci-hcd.0.auto: Max number of devices this xHCI host supports is 127. xhci-hcd xhci-hcd.0.auto: Error while assigning device slot ID xhci-hcd xhci-hcd.0.auto: Max number of devices this xHCI host supports is 127. xhci-hcd xhci-hcd.0.auto: Error while assigning device slot ID xhci-hcd xhci-hcd.0.auto: Max number of devices this xHCI host supports is 127. PM: resume of devices complete after 75567.769 msecs Restarting tasks ... usb 1-1: USB disconnect, device number 2 usb 2-1: USB disconnect, device number 2 usb 2-1.1: USB disconnect, device number 3 done. root@phoenix:~# Signed-off-by: Sriram Dash <sriram.dash@xxxxxxx> Signed-off-by: Rajesh Bhagat <rajesh.bhagat@xxxxxxx> --- drivers/usb/core/hub.c | 12 ++++++++---- drivers/usb/host/xhci-ring.c | 2 +- 2 files changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 38cc4ba..c906018 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2897,10 +2897,14 @@ done: /* The xHC may think the device is already reset, * so ignore the status. */ - if (hcd->driver->reset_device) - hcd->driver->reset_device(hcd, udev); - - usb_set_device_state(udev, USB_STATE_DEFAULT); + if (hcd->driver->reset_device) { + status = hcd->driver->reset_device(hcd, udev); + if (status == 0) + usb_set_device_state(udev, USB_STATE_DEFAULT); + else + usb_set_device_state(udev, USB_STATE_NOTATTACHED); + } else + usb_set_device_state(udev, USB_STATE_DEFAULT); } } else { if (udev) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 7cf6621..be8fd61 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1272,9 +1272,9 @@ void xhci_handle_command_timeout(unsigned long data) spin_unlock_irqrestore(&xhci->lock, flags); xhci_dbg(xhci, "Command timeout\n"); ret = xhci_abort_cmd_ring(xhci); + xhci_cleanup_command_queue(xhci); if (unlikely(ret == -ESHUTDOWN)) { xhci_err(xhci, "Abort command ring failed\n"); - xhci_cleanup_command_queue(xhci); usb_hc_died(xhci_to_hcd(xhci)->primary_hcd); xhci_dbg(xhci, "xHCI host controller is dead.\n"); } -- 1.7.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html