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authorMathias Nyman <mathias.nyman@linux.intel.com>2017-07-20 14:48:29 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-07-20 14:40:36 +0200
commita54408d0a004757789863d74e29c2297edae0b4d (patch)
tree66173ead002352eb4ec98032ef623e31f8a62793 /drivers/usb
parent28a2369f7d72ece55089f33e7d7b9c1223673cc3 (diff)
downloadlinux-0-day-a54408d0a004757789863d74e29c2297edae0b4d.tar.gz
linux-0-day-a54408d0a004757789863d74e29c2297edae0b4d.tar.xz
xhci: fix 20000ms port resume timeout
A uncleared PLC (port link change) bit will prevent furuther port event interrupts for that port. Leaving it uncleared caused get_port_status() to timeout after 20000ms while waiting to get the final port event interrupt for resume -> U0 state change. This is a targeted fix for a specific case where we get a port resume event racing with xhci resume. The port event interrupt handler notices xHC is not yet running and bails out early, leaving PLC uncleared. The whole xhci port resuming needs more attention, but while working on it it anyways makes sense to always ensure PLC is cleared in get_port_status before setting a new link state and waiting for its completion. Cc: <stable@vger.kernel.org> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/host/xhci-hub.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 364f602750435..9ef5f68e32131 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -904,6 +904,9 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
clear_bit(wIndex, &bus_state->resuming_ports);
set_bit(wIndex, &bus_state->rexit_ports);
+
+ xhci_test_and_clear_bit(xhci, port_array, wIndex,
+ PORT_PLC);
xhci_set_link_state(xhci, port_array, wIndex,
XDEV_U0);