| From 72978b2fe2f2cdf9f319c6c6dcdbe92b38de2be2 Mon Sep 17 00:00:00 2001 |
| From: Ross Lagerwall <ross.lagerwall@citrix.com> |
| Date: Mon, 19 Jan 2015 13:19:38 +0000 |
| Subject: xen/manage: Fix USB interaction issues when resuming |
| |
| From: Ross Lagerwall <ross.lagerwall@citrix.com> |
| |
| commit 72978b2fe2f2cdf9f319c6c6dcdbe92b38de2be2 upstream. |
| |
| Commit 61a734d305e1 ("xen/manage: Always freeze/thaw processes when |
| suspend/resuming") ensured that userspace processes were always frozen |
| before suspending to reduce interaction issues when resuming devices. |
| However, freeze_processes() does not freeze kernel threads. Freeze |
| kernel threads as well to prevent deadlocks with the khubd thread when |
| resuming devices. |
| |
| This is what native suspend and resume does. |
| |
| Example deadlock: |
| [ 7279.648010] [<ffffffff81446bde>] ? xen_poll_irq_timeout+0x3e/0x50 |
| [ 7279.648010] [<ffffffff81448d60>] xen_poll_irq+0x10/0x20 |
| [ 7279.648010] [<ffffffff81011723>] xen_lock_spinning+0xb3/0x120 |
| [ 7279.648010] [<ffffffff810115d1>] __raw_callee_save_xen_lock_spinning+0x11/0x20 |
| [ 7279.648010] [<ffffffff815620b6>] ? usb_control_msg+0xe6/0x120 |
| [ 7279.648010] [<ffffffff81747e50>] ? _raw_spin_lock_irq+0x50/0x60 |
| [ 7279.648010] [<ffffffff8174522c>] wait_for_completion+0xac/0x160 |
| [ 7279.648010] [<ffffffff8109c520>] ? try_to_wake_up+0x2c0/0x2c0 |
| [ 7279.648010] [<ffffffff814b60f2>] dpm_wait+0x32/0x40 |
| [ 7279.648010] [<ffffffff814b6eb0>] device_resume+0x90/0x210 |
| [ 7279.648010] [<ffffffff814b7d71>] dpm_resume+0x121/0x250 |
| [ 7279.648010] [<ffffffff8144c570>] ? xenbus_dev_request_and_reply+0xc0/0xc0 |
| [ 7279.648010] [<ffffffff814b80d5>] dpm_resume_end+0x15/0x30 |
| [ 7279.648010] [<ffffffff81449fba>] do_suspend+0x10a/0x200 |
| [ 7279.648010] [<ffffffff8144a2f0>] ? xen_pre_suspend+0x20/0x20 |
| [ 7279.648010] [<ffffffff8144a1d0>] shutdown_handler+0x120/0x150 |
| [ 7279.648010] [<ffffffff8144c60f>] xenwatch_thread+0x9f/0x160 |
| [ 7279.648010] [<ffffffff810ac510>] ? finish_wait+0x80/0x80 |
| [ 7279.648010] [<ffffffff8108d189>] kthread+0xc9/0xe0 |
| [ 7279.648010] [<ffffffff8108d0c0>] ? flush_kthread_worker+0x80/0x80 |
| [ 7279.648010] [<ffffffff8175087c>] ret_from_fork+0x7c/0xb0 |
| [ 7279.648010] [<ffffffff8108d0c0>] ? flush_kthread_worker+0x80/0x80 |
| |
| [ 7441.216287] INFO: task khubd:89 blocked for more than 120 seconds. |
| [ 7441.219457] Tainted: G X 3.13.11-ckt12.kz #1 |
| [ 7441.222176] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. |
| [ 7441.225827] khubd D ffff88003f433440 0 89 2 0x00000000 |
| [ 7441.229258] ffff88003ceb9b98 0000000000000046 ffff88003ce83000 0000000000013440 |
| [ 7441.232959] ffff88003ceb9fd8 0000000000013440 ffff88003cd13000 ffff88003ce83000 |
| [ 7441.236658] 0000000000000286 ffff88003d3e0000 ffff88003ceb9bd0 00000001001aa01e |
| [ 7441.240415] Call Trace: |
| [ 7441.241614] [<ffffffff817442f9>] schedule+0x29/0x70 |
| [ 7441.243930] [<ffffffff81743406>] schedule_timeout+0x166/0x2c0 |
| [ 7441.246681] [<ffffffff81075b80>] ? call_timer_fn+0x110/0x110 |
| [ 7441.249339] [<ffffffff8174357e>] schedule_timeout_uninterruptible+0x1e/0x20 |
| [ 7441.252644] [<ffffffff81077710>] msleep+0x20/0x30 |
| [ 7441.254812] [<ffffffff81555f00>] hub_port_reset+0xf0/0x580 |
| [ 7441.257400] [<ffffffff81558465>] hub_port_init+0x75/0xb40 |
| [ 7441.259981] [<ffffffff814bb3c9>] ? update_autosuspend+0x39/0x60 |
| [ 7441.262817] [<ffffffff814bb4f0>] ? pm_runtime_set_autosuspend_delay+0x50/0xa0 |
| [ 7441.266212] [<ffffffff8155a64a>] hub_thread+0x71a/0x1750 |
| [ 7441.268728] [<ffffffff810ac510>] ? finish_wait+0x80/0x80 |
| [ 7441.271272] [<ffffffff81559f30>] ? usb_port_resume+0x670/0x670 |
| [ 7441.274067] [<ffffffff8108d189>] kthread+0xc9/0xe0 |
| [ 7441.276305] [<ffffffff8108d0c0>] ? flush_kthread_worker+0x80/0x80 |
| [ 7441.279131] [<ffffffff8175087c>] ret_from_fork+0x7c/0xb0 |
| [ 7441.281659] [<ffffffff8108d0c0>] ? flush_kthread_worker+0x80/0x80 |
| |
| Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> |
| Signed-off-by: David Vrabel <david.vrabel@citrix.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/xen/manage.c | 8 +++++++- |
| 1 file changed, 7 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/xen/manage.c |
| +++ b/drivers/xen/manage.c |
| @@ -113,10 +113,16 @@ static void do_suspend(void) |
| |
| err = freeze_processes(); |
| if (err) { |
| - pr_err("%s: freeze failed %d\n", __func__, err); |
| + pr_err("%s: freeze processes failed %d\n", __func__, err); |
| goto out; |
| } |
| |
| + err = freeze_kernel_threads(); |
| + if (err) { |
| + pr_err("%s: freeze kernel threads failed %d\n", __func__, err); |
| + goto out_thaw; |
| + } |
| + |
| err = dpm_suspend_start(PMSG_FREEZE); |
| if (err) { |
| pr_err("%s: dpm_suspend_start %d\n", __func__, err); |
