4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> [ Upstream commit 74cb319bd97dd62881f97ea5a3228f7c2546bf56 ] pm_runtime_put_sync() gets called everytime in xhci_dbc_stop(). If dbc is not started, this makes the runtime PM counter incorrectly becomes 0, and calls autosuspend function. Then we'll keep seeing this: [54664.762220] xhci_hcd 0000:00:14.0: Root hub is not suspended So only calls pm_runtime_put_sync() when dbc was started. Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/host/xhci-dbgcap.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/drivers/usb/host/xhci-dbgcap.c +++ b/drivers/usb/host/xhci-dbgcap.c @@ -507,16 +507,18 @@ static int xhci_do_dbc_start(struct xhci return 0; } -static void xhci_do_dbc_stop(struct xhci_hcd *xhci) +static int xhci_do_dbc_stop(struct xhci_hcd *xhci) { struct xhci_dbc *dbc = xhci->dbc; if (dbc->state == DS_DISABLED) - return; + return -1; writel(0, &dbc->regs->control); xhci_dbc_mem_cleanup(xhci); dbc->state = DS_DISABLED; + + return 0; } static int xhci_dbc_start(struct xhci_hcd *xhci) @@ -543,6 +545,7 @@ static int xhci_dbc_start(struct xhci_hc static void xhci_dbc_stop(struct xhci_hcd *xhci) { + int ret; unsigned long flags; struct xhci_dbc *dbc = xhci->dbc; struct dbc_port *port = &dbc->port; @@ -555,10 +558,11 @@ static void xhci_dbc_stop(struct xhci_hc xhci_dbc_tty_unregister_device(xhci); spin_lock_irqsave(&dbc->lock, flags); - xhci_do_dbc_stop(xhci); + ret = xhci_do_dbc_stop(xhci); spin_unlock_irqrestore(&dbc->lock, flags); - pm_runtime_put_sync(xhci_to_hcd(xhci)->self.controller); + if (!ret) + pm_runtime_put_sync(xhci_to_hcd(xhci)->self.controller); } static void