[PATCH 3.10 173/268] xhci: fix 10 second timeout on removal of PCI hotpluggable xhci controllers

Willy Tarreau
2017-06-19T18:43:39Z

From: Mathias Nyman <mathias.nyman@linux.intel.com>

commit 98d74f9ceaefc2b6c4a6440050163a83be0abede upstream.

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.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
drivers/usb/host/xhci-pci.c | 1 +
drivers/usb/host/xhci.c | 6 ++++--
drivers/usb/host/xhci.h | 1 +
3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 2320e20..cae9881 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -224,6 +224,7 @@ 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.c b/drivers/usb/host/xhci.c
index 507677b..0e7dccc 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -139,7 +139,8 @@ 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;
}
@@ -2693,7 +2694,8 @@ 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);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index deb2537..15e796f 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1493,6 +1493,7 @@ 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.rc2.1.gbe9624a