On Mon, Nov 25, 2013 at 11:41:47AM -0700, Shuah Khan wrote:
> I started seeing the following on my Samsung Series on 3.12.1
>
> Is this bad? Looks like the following WARN_ON is firing:
>
> drivers/usb/host/xhci.c:
>
> if (WARN_ON(!virt_dev)) {
> /*
> * In plug/unplug torture test with an NEC controller,
> * a zero-dereference was observed once due to
> virt_dev = 0.
> * Print useful debug rather than crash if it is
> observed again!
> */
> xhci_warn(xhci, "Virt dev invalid for slot_id 0x%x!\n",
> udev->slot_id);
> return -EINVAL;
> }
As the comment says, the WARN_ON was there so we can track down why this
specific NULL pointer dereference bug could have been hit.
What are the specific steps to reproduce this? It looks like it's
coming from a device resume path. Did you have auto-suspend enabled for
your USB devices, or did this warning occur right after an S3 resume?
Can you enable CONFIG_USB_DEBUG and CONFIG_DYNAMIC_DEBUG, and send me
dmesg starting from just before you trigger the WARN_ON()? I need to
see what the xHCI driver state that causes this might be.
Sarah Sharp
> [ 565.276187] ------------[ cut here ]------------
> [ 565.276198] WARNING: CPU: 2 PID: 2228 at
> drivers/usb/host/xhci.c:3748 xhci_address_device+0x57b/0x630()
> [ 565.276262] Modules linked in: parport_pc ppdev arc4 iwldvm
> rfcomm bnep mac80211 i915 ext2 joydev x86_pkg_temp_thermal coretemp
> kvm_intel kvm iwlwifi uvcvideo videobuf2_vmalloc cfg80211
> videobuf2_memops snd_hda_codec_hdmi videobuf2_core videodev
> drm_kms_helper snd_hda_codec_realtek ghash_clmulni_intel aesni_intel
> drm snd_hda_intel aes_x86_64 btusb media ablk_helper snd_hda_codec
> cryptd bluetooth lrw gf128mul glue_helper hid_generic samsung_laptop
> usbhid tpm_infineon hid snd_hwdep snd_pcm psmouse snd_page_alloc
> snd_timer microcode i2c_algo_bit lpc_ich serio_raw lp parport video
> wmi tpm_tis mac_hid r8169 mii
> [ 565.276267] CPU: 2 PID: 2228 Comm: kworker/u16:39 Not tainted 3.12.1+ #11
> [ 565.276269] Hardware name: SAMSUNG ELECTRONICS CO., LTD.
> 900X3C/900X3D/900X4C/900X4D/SAMSUNG_NP1234567890, BIOS P03AAC
> 07/12/2012
> [ 565.276278] Workqueue: events_unbound async_run_entry_fn
> [ 565.276285] 0000000000000009 ffff88002fb0fb00 ffffffff816bf0c1
> 0000000000000000
> [ 565.276289] ffff88002fb0fb38 ffffffff8104d5fd ffff88040cc7e000
> 0000000000000000
> [ 565.276293] ffff8803f0195800 0000000000000002 0000000000000000
> ffff88002fb0fb48
> [ 565.276294] Call Trace:
> [ 565.276307] [<ffffffff816bf0c1>] dump_stack+0x45/0x56
> [ 565.276314] [<ffffffff8104d5fd>] warn_slowpath_common+0x7d/0xa0
> [ 565.276318] [<ffffffff8104d6da>] warn_slowpath_null+0x1a/0x20
> [ 565.276324] [<ffffffff8150a43b>] xhci_address_device+0x57b/0x630
> [ 565.276330] [<ffffffff814d49d4>] hub_port_init+0x1f4/0xa40
> [ 565.276335] [<ffffffff814d5336>] usb_reset_and_verify_device+0x116/0x730
> [ 565.276340] [<ffffffff814d2ced>] ? hub_port_status+0xdd/0x120
> [ 565.276345] [<ffffffff814d7bd0>] usb_port_resume+0x2f0/0x5c0
> [ 565.276352] [<ffffffff814eb535>] generic_resume+0x15/0x30
> [ 565.276358] [<ffffffff814e26e7>] usb_resume_both+0x107/0x150
> [ 565.276366] [<ffffffff814d1e30>] ? usb_for_each_dev+0x30/0x30
> [ 565.276372] [<ffffffff814e325f>] usb_resume+0x1f/0xd0
> [ 565.276377] [<ffffffff814d1e30>] ? usb_for_each_dev+0x30/0x30
> [ 565.276383] [<ffffffff814d1e43>] usb_dev_restore+0x13/0x20
> [ 565.276392] [<ffffffff8143c179>] dpm_run_callback+0x49/0xa0
> [ 565.276398] [<ffffffff8143c2d6>] device_resume+0xc6/0x1f0
> [ 565.276404] [<ffffffff8143c41d>] async_resume+0x1d/0x50
> [ 565.276409] [<ffffffff810766c7>] async_run_entry_fn+0x37/0x130
> [ 565.276418] [<ffffffff81068357>] process_one_work+0x177/0x410
> [ 565.276424] [<ffffffff81068f91>] worker_thread+0x121/0x3a0
> [ 565.276431] [<ffffffff81068e70>] ? manage_workers.isra.25+0x2b0/0x2b0
> [ 565.276436] [<ffffffff8106f730>] kthread+0xc0/0xd0
> [ 565.276442] [<ffffffff8106f670>] ? kthread_create_on_node+0x120/0x120
> [ 565.276448] [<ffffffff816ced2c>] ret_from_fork+0x7c/0xb0
> [ 565.276453] [<ffffffff8106f670>] ? kthread_create_on_node+0x120/0x120
> [ 565.276456] ---[ end trace 115d14352276d432 ]---
> [ 565.276460] xhci_hcd 0000:03:00.0: Virt dev invalid for slot_id 0x1!
> [ 565.478224] ------------[ cut here ]------------
>
> --
> Shuah Khan
> Senior Linux Kernel Developer - Open Source Group
> Samsung Research America(Silicon Valley)
> shuah.kh@xxxxxxxxxxx | (970) 672-0658
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