[2/2] usb: xhci: dbc: Don't decrement runtime PM counter if DBC is not started

Message ID 20180703083808.15858-3-kai.heng.feng@canonical.com
State New
Headers show
Series
  • Fix "xhci_hcd 0000:00:14.0: Root hub is not suspended"
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Commit Message

Kai-Heng Feng July 3, 2018, 8:38 a.m.
BugLink: https://bugs.launchpad.net/bugs/1779823

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@canonical.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 74cb319bd97dd62881f97ea5a3228f7c2546bf56 git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-linus)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/usb/host/xhci-dbgcap.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

Patch

diff --git a/drivers/usb/host/xhci-dbgcap.c b/drivers/usb/host/xhci-dbgcap.c
index 1fa4ca15779e..3f32a0f8082f 100644
--- 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_hcd *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_hcd *xhci)
 
 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_hcd *xhci)
 		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