patch "xhci: fix 10 second timeout on removal of PCI hotpluggable xhci" added to usb-linus

patch "xhci: fix 10 second timeout on removal of PCI hotpluggable xhci" added to usb-linus

[gregkh]

This is a note to let you know that I've just added the patch titled

    xhci: fix 10 second timeout on removal of PCI hotpluggable xhci

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


>From 98d74f9ceaefc2b6c4a6440050163a83be0abede Mon Sep 17 00:00:00 2001
From: Mathias Nyman <mathias.nyman@linux.intel.com>
Date: Fri, 8 Apr 2016 16:25:10 +0300
Subject: xhci: fix 10 second timeout on removal of PCI hotpluggable xhci
 controllers

PCI hotpluggable xhci controllers such as some Alpine Ridge solutions will
remove the xhci controller from the PCI bus when the last USB device is
disconnected.

Add a flag to indicate that the host is being removed to avoid queueing
configure_endpoint commands for the dropped endpoints.
For PCI hotplugged controllers this will prevent 5 second command timeouts
For static xhci controllers the configure_endpoint command is not needed
in the removal case as everything will be returned, freed, and the
controller is reset.

For now the flag is only set for PCI connected host controllers.

Cc: <stable@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/host/xhci-pci.c  | 1 +
 drivers/usb/host/xhci-ring.c | 3 ++-
 drivers/usb/host/xhci.c      | 8 +++++---
 drivers/usb/host/xhci.h      | 1 +
 4 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 071b34ae9c4e..48672fac7ff3 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -304,6 +304,7 @@ static void xhci_pci_remove(struct pci_dev *dev)
 	struct xhci_hcd *xhci;
 
 	xhci = hcd_to_xhci(pci_get_drvdata(dev));
+	xhci->xhc_state |= XHCI_STATE_REMOVING;
 	if (xhci->shared_hcd) {
 		usb_remove_hcd(xhci->shared_hcd);
 		usb_put_hcd(xhci->shared_hcd);
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 7cf66212ceae..99b4ff42f7a0 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -4004,7 +4004,8 @@ static int queue_command(struct xhci_hcd *xhci, struct xhci_command *cmd,
 	int reserved_trbs = xhci->cmd_ring_reserved_trbs;
 	int ret;
 
-	if (xhci->xhc_state) {
+	if ((xhci->xhc_state & XHCI_STATE_DYING) ||
+		(xhci->xhc_state & XHCI_STATE_HALTED)) {
 		xhci_dbg(xhci, "xHCI dying or halted, can't queue_command\n");
 		return -ESHUTDOWN;
 	}
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 9283d3331b59..9e71c96ad74a 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -147,7 +147,8 @@ static int xhci_start(struct xhci_hcd *xhci)
 				"waited %u microseconds.\n",
 				XHCI_MAX_HALT_USEC);
 	if (!ret)
-		xhci->xhc_state &= ~(XHCI_STATE_HALTED | XHCI_STATE_DYING);
+		/* clear state flags. Including dying, halted or removing */
+		xhci->xhc_state = 0;
 
 	return ret;
 }
@@ -2773,7 +2774,8 @@ int xhci_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
 	if (ret <= 0)
 		return ret;
 	xhci = hcd_to_xhci(hcd);
-	if (xhci->xhc_state & XHCI_STATE_DYING)
+	if ((xhci->xhc_state & XHCI_STATE_DYING) ||
+		(xhci->xhc_state & XHCI_STATE_REMOVING))
 		return -ENODEV;
 
 	xhci_dbg(xhci, "%s called for udev %p\n", __func__, udev);
@@ -3820,7 +3822,7 @@ static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,
 
 	mutex_lock(&xhci->mutex);
 
-	if (xhci->xhc_state)	/* dying or halted */
+	if (xhci->xhc_state)	/* dying, removing or halted */
 		goto out;
 
 	if (!udev->slot_id) {
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 70f215c20b2b..6c629c97f8ad 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1605,6 +1605,7 @@ struct xhci_hcd {
  */
 #define XHCI_STATE_DYING	(1 << 0)
 #define XHCI_STATE_HALTED	(1 << 1)
+#define XHCI_STATE_REMOVING	(1 << 2)
 	/* Statistics */
 	int			error_bitmask;
 	unsigned int		quirks;
-- 
2.8.0