[3.19.y-ckt stable] Patch "usb: xhci: fix xhci locking up during hcd remove" has been added to the 3.19.y-ckt tree
Kamal Mostafa
kamal at canonical.com
Tue Apr 26 19:54:08 UTC 2016
This is a note to let you know that I have just added a patch titled
usb: xhci: fix xhci locking up during hcd remove
to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree
which can be found at:
http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue
This patch is scheduled to be released in version 3.19.8-ckt20.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
---8<------------------------------------------------------------
>From dfc09d7f907e4ef63989919f0599b0b422ec1e0b Mon Sep 17 00:00:00 2001
From: Roger Quadros <rogerq at ti.com>
Date: Fri, 29 May 2015 17:01:49 +0300
Subject: usb: xhci: fix xhci locking up during hcd remove
commit ad6b1d914a9e07f3b9a9ae3396f3c840d0070539 upstream.
The problem seems to be that if a new device is detected
while we have already removed the shared HCD, then many of the
xhci operations (e.g. xhci_alloc_dev(), xhci_setup_device())
hang as command never completes.
I don't think XHCI can operate without the shared HCD as we've
already called xhci_halt() in xhci_only_stop_hcd() when shared HCD
goes away. We need to prevent new commands from being queued
not only when HCD is dying but also when HCD is halted.
The following lockup was detected while testing the otg state
machine.
[ 178.199951] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller
[ 178.205799] xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 1
[ 178.214458] xhci-hcd xhci-hcd.0.auto: hcc params 0x0220f04c hci version 0x100 quirks 0x00010010
[ 178.223619] xhci-hcd xhci-hcd.0.auto: irq 400, io mem 0x48890000
[ 178.230677] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
[ 178.237796] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 178.245358] usb usb1: Product: xHCI Host Controller
[ 178.250483] usb usb1: Manufacturer: Linux 4.0.0-rc1-00024-g6111320 xhci-hcd
[ 178.257783] usb usb1: SerialNumber: xhci-hcd.0.auto
[ 178.267014] hub 1-0:1.0: USB hub found
[ 178.272108] hub 1-0:1.0: 1 port detected
[ 178.278371] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller
[ 178.284171] xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 2
[ 178.294038] usb usb2: New USB device found, idVendor=1d6b, idProduct=0003
[ 178.301183] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 178.308776] usb usb2: Product: xHCI Host Controller
[ 178.313902] usb usb2: Manufacturer: Linux 4.0.0-rc1-00024-g6111320 xhci-hcd
[ 178.321222] usb usb2: SerialNumber: xhci-hcd.0.auto
[ 178.329061] hub 2-0:1.0: USB hub found
[ 178.333126] hub 2-0:1.0: 1 port detected
[ 178.567585] dwc3 48890000.usb: usb_otg_start_host 0
[ 178.572707] xhci-hcd xhci-hcd.0.auto: remove, state 4
[ 178.578064] usb usb2: USB disconnect, device number 1
[ 178.586565] xhci-hcd xhci-hcd.0.auto: USB bus 2 deregistered
[ 178.592585] xhci-hcd xhci-hcd.0.auto: remove, state 1
[ 178.597924] usb usb1: USB disconnect, device number 1
[ 178.603248] usb 1-1: new high-speed USB device number 2 using xhci-hcd
[ 190.597337] INFO: task kworker/u4:0:6 blocked for more than 10 seconds.
[ 190.604273] Not tainted 4.0.0-rc1-00024-g6111320 #1058
[ 190.610228] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 190.618443] kworker/u4:0 D c05c0ac0 0 6 2 0x00000000
[ 190.625120] Workqueue: usb_otg usb_otg_work
[ 190.629533] [<c05c0ac0>] (__schedule) from [<c05c10ac>] (schedule+0x34/0x98)
[ 190.636915] [<c05c10ac>] (schedule) from [<c05c1318>] (schedule_preempt_disabled+0xc/0x10)
[ 190.645591] [<c05c1318>] (schedule_preempt_disabled) from [<c05c23d0>] (mutex_lock_nested+0x1ac/0x3fc)
[ 190.655353] [<c05c23d0>] (mutex_lock_nested) from [<c046cf8c>] (usb_disconnect+0x3c/0x208)
[ 190.664043] [<c046cf8c>] (usb_disconnect) from [<c0470cf0>] (_usb_remove_hcd+0x98/0x1d8)
[ 190.672535] [<c0470cf0>] (_usb_remove_hcd) from [<c0485da8>] (usb_otg_start_host+0x50/0xf4)
[ 190.681299] [<c0485da8>] (usb_otg_start_host) from [<c04849a4>] (otg_set_protocol+0x5c/0xd0)
[ 190.690153] [<c04849a4>] (otg_set_protocol) from [<c0484b88>] (otg_set_state+0x170/0xbfc)
[ 190.698735] [<c0484b88>] (otg_set_state) from [<c0485740>] (otg_statemachine+0x12c/0x470)
[ 190.707326] [<c0485740>] (otg_statemachine) from [<c0053c84>] (process_one_work+0x1b4/0x4a0)
[ 190.716162] [<c0053c84>] (process_one_work) from [<c00540f8>] (worker_thread+0x154/0x44c)
[ 190.724742] [<c00540f8>] (worker_thread) from [<c0058f88>] (kthread+0xd4/0xf0)
[ 190.732328] [<c0058f88>] (kthread) from [<c000e810>] (ret_from_fork+0x14/0x24)
[ 190.739898] 5 locks held by kworker/u4:0/6:
[ 190.744274] #0: ("%s""usb_otg"){.+.+.+}, at: [<c0053bf4>] process_one_work+0x124/0x4a0
[ 190.752799] #1: ((&otgd->work)){+.+.+.}, at: [<c0053bf4>] process_one_work+0x124/0x4a0
[ 190.761326] #2: (&otgd->fsm.lock){+.+.+.}, at: [<c048562c>] otg_statemachine+0x18/0x470
[ 190.769934] #3: (usb_bus_list_lock){+.+.+.}, at: [<c0470ce8>] _usb_remove_hcd+0x90/0x1d8
[ 190.778635] #4: (&dev->mutex){......}, at: [<c046cf8c>] usb_disconnect+0x3c/0x208
[ 190.786700] INFO: task kworker/1:0:14 blocked for more than 10 seconds.
[ 190.793633] Not tainted 4.0.0-rc1-00024-g6111320 #1058
[ 190.799567] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 190.807783] kworker/1:0 D c05c0ac0 0 14 2 0x00000000
[ 190.814457] Workqueue: usb_hub_wq hub_event
[ 190.818866] [<c05c0ac0>] (__schedule) from [<c05c10ac>] (schedule+0x34/0x98)
[ 190.826252] [<c05c10ac>] (schedule) from [<c05c4e40>] (schedule_timeout+0x13c/0x1ec)
[ 190.834377] [<c05c4e40>] (schedule_timeout) from [<c05c19f0>] (wait_for_common+0xbc/0x150)
[ 190.843062] [<c05c19f0>] (wait_for_common) from [<bf068a3c>] (xhci_setup_device+0x164/0x5cc [xhci_hcd])
[ 190.852986] [<bf068a3c>] (xhci_setup_device [xhci_hcd]) from [<c046b7f4>] (hub_port_init+0x3f4/0xb10)
[ 190.862667] [<c046b7f4>] (hub_port_init) from [<c046eb64>] (hub_event+0x704/0x1018)
[ 190.870704] [<c046eb64>] (hub_event) from [<c0053c84>] (process_one_work+0x1b4/0x4a0)
[ 190.878919] [<c0053c84>] (process_one_work) from [<c00540f8>] (worker_thread+0x154/0x44c)
[ 190.887503] [<c00540f8>] (worker_thread) from [<c0058f88>] (kthread+0xd4/0xf0)
[ 190.895076] [<c0058f88>] (kthread) from [<c000e810>] (ret_from_fork+0x14/0x24)
[ 190.902650] 5 locks held by kworker/1:0/14:
[ 190.907023] #0: ("usb_hub_wq"){.+.+.+}, at: [<c0053bf4>] process_one_work+0x124/0x4a0
[ 190.915454] #1: ((&hub->events)){+.+.+.}, at: [<c0053bf4>] process_one_work+0x124/0x4a0
[ 190.924070] #2: (&dev->mutex){......}, at: [<c046e490>] hub_event+0x30/0x1018
[ 190.931768] #3: (&port_dev->status_lock){+.+.+.}, at: [<c046eb50>] hub_event+0x6f0/0x1018
[ 190.940558] #4: (&bus->usb_address0_mutex){+.+.+.}, at: [<c046b458>] hub_port_init+0x58/0xb10
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-ring.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index fb9c10e..007f68d 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3804,8 +3804,11 @@ 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 & XHCI_STATE_DYING)
+
+ if (xhci->xhc_state) {
+ xhci_dbg(xhci, "xHCI dying or halted, can't queue_command\n");
return -ESHUTDOWN;
+ }
if (!command_must_succeed)
reserved_trbs++;
--
2.7.4
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