[3.16.y-ckt stable] Patch "usb: xhci: exit early in xhci_setup_device() if we're halted or dying" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    usb: xhci: exit early in xhci_setup_device() if we're halted or dying

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.19.8-ckt9.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From b70276717d0146d486222250f50de2aa7c02fef2 Mon Sep 17 00:00:00 2001
From: Roger Quadros <rogerq at ti.com>
Date: Mon, 21 Sep 2015 17:46:15 +0300
Subject: usb: xhci: exit early in xhci_setup_device() if we're halted or dying

commit 448116bfa856d3c076fa7178ed96661a008a5d45 upstream.

During quick plug/removal of OTG adapter during dual-role testing
it can happen that xhci_alloc_device() is called for the newly
detected device after the DRD library has called xhci_stop to
remove the HCD.

If that is the case, just fail early to prevent the following warning.

[  154.732649] hub 4-0:1.0: USB hub found
[  154.742204] hub 4-0:1.0: 1 port detected
[  154.824458] hub 3-0:1.0: state 7 ports 1 chg 0002 evt 0000
[  154.854609] hub 4-0:1.0: state 7 ports 1 chg 0000 evt 0000
[  154.944430] usb 3-1: new high-speed USB device number 2 using xhci-hcd
[  154.951009] xhci-hcd xhci-hcd.0.auto: xhci_setup_device
[  155.038191] xhci-hcd xhci-hcd.0.auto: remove, state 4
[  155.043315] usb usb4: USB disconnect, device number 1
[  155.055270] xhci-hcd xhci-hcd.0.auto: xhci_stop
[  155.060094] xhci-hcd xhci-hcd.0.auto: USB bus 4 deregistered
[  155.066576] xhci-hcd xhci-hcd.0.auto: remove, state 1
[  155.071710] usb usb3: USB disconnect, device number 1
[  155.077124] xhci-hcd xhci-hcd.0.auto: xhci_setup_device
[  155.082389] ------------[ cut here ]------------
[  155.087690] WARNING: CPU: 0 PID: 72 at drivers/usb/host/xhci.c:3800 xhci_setup_device+0x410/0x484 [xhci_hcd]()
[  155.097861] Modules linked in: sd_mod usb_storage scsi_mod usb_f_ss_lb g_zero libcomposite ipv6 xhci_plat_hcd xhci_hcd usbcore dwc3 udc_core evdev ti_am335x_adc joydev kfifo_buf industrialio snd_soc_simple_cc
[  155.146734] CPU: 0 PID: 72 Comm: kworker/0:3 Tainted: G        W       4.1.4-00834-gcd9380b-dirty #50
[  155.156073] Hardware name: Generic AM43 (Flattened Device Tree)
[  155.162117] Workqueue: usb_hub_wq hub_event [usbcore]
[  155.167249] Backtrace:
[  155.169751] [<c0012af0>] (dump_backtrace) from [<c0012c8c>] (show_stack+0x18/0x1c)
[  155.177390]  r6:c089d4a4 r5:ffffffff r4:00000000 r3:ee46c000
[  155.183137] [<c0012c74>] (show_stack) from [<c05f7c14>] (dump_stack+0x84/0xd0)
[  155.190446] [<c05f7b90>] (dump_stack) from [<c00439ac>] (warn_slowpath_common+0x80/0xbc)
[  155.198605]  r7:00000009 r6:00000ed8 r5:bf27eb70 r4:00000000
[  155.204348] [<c004392c>] (warn_slowpath_common) from [<c0043a0c>] (warn_slowpath_null+0x24/0x2c)
[  155.213202]  r8:ee49f000 r7:ee7c0004 r6:00000000 r5:ee7c0158 r4:ee7c0000
[  155.220051] [<c00439e8>] (warn_slowpath_null) from [<bf27eb70>] (xhci_setup_device+0x410/0x484 [xhci_hcd])
[  155.229816] [<bf27e760>] (xhci_setup_device [xhci_hcd]) from [<bf27ec10>] (xhci_address_device+0x14/0x18 [xhci_hcd])
[  155.240415]  r10:ee598200 r9:00000001 r8:00000002 r7:00000001 r6:00000003 r5:00000002
[  155.248363]  r4:ee49f000
[  155.250978] [<bf27ebfc>] (xhci_address_device [xhci_hcd]) from [<bf20cb94>] (hub_port_init+0x1b8/0xa9c [usbcore])
[  155.261403] [<bf20c9dc>] (hub_port_init [usbcore]) from [<bf2101e0>] (hub_event+0x738/0x1020 [usbcore])
[  155.270874]  r10:ee598200 r9:ee7c0000 r8:ee7c0038 r7:ee518800 r6:ee49f000 r5:00000001
[  155.278822]  r4:00000000
[  155.281426] [<bf20faa8>] (hub_event [usbcore]) from [<c005754c>] (process_one_work+0x128/0x340)
[  155.290196]  r10:00000000 r9:00000003 r8:00000000 r7:fedfa000 r6:eeec5400 r5:ee598314
[  155.298151]  r4:ee434380
[  155.300718] [<c0057424>] (process_one_work) from [<c00578f8>] (worker_thread+0x158/0x49c)
[  155.308963]  r10:ee434380 r9:00000003 r8:eeec5400 r7:00000008 r6:ee434398 r5:eeec5400
[  155.316913]  r4:eeec5414
[  155.319482] [<c00577a0>] (worker_thread) from [<c005cc40>] (kthread+0xdc/0xf8)
[  155.326765]  r10:00000000 r9:00000000 r8:00000000 r7:c00577a0 r6:ee434380 r5:ee4441c0
[  155.334713]  r4:00000000 r3:00000000
[  155.338341] [<c005cb64>] (kthread) from [<c000fc08>] (ret_from_fork+0x14/0x2c)
[  155.345626]  r7:00000000 r6:00000000 r5:c005cb64 r4:ee4441c0
[  155.356108] ---[ end trace a58d34c223b190e6 ]---
[  155.360783] xhci-hcd xhci-hcd.0.auto: Virt dev invalid for slot_id 0x1!
[  155.574404] xhci-hcd xhci-hcd.0.auto: xhci_setup_device
[  155.579667] ------------[ cut here ]------------

Signed-off-by: Roger Quadros <rogerq at ti.com>
Signed-off-by: Mathias Nyman <mathias.nyman at linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/usb/host/xhci.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 0dfda9e..0612a5b 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3799,6 +3799,9 @@ static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,

 	mutex_lock(&xhci->mutex);

+	if (xhci->xhc_state)	/* dying or halted */
+		goto out;
+
 	if (!udev->slot_id) {
 		xhci_dbg_trace(xhci, trace_xhci_dbg_address,
 				"Bad Slot ID %d", udev->slot_id);
--
1.9.1