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From:   Benjamin Tissoires <benjamin.tissoires@gmail.com>
Date:   Thu, 31 May 2018 12:00:58 +0200
Message-ID: <CAN+gG=HZQdANHx6pUE9Agm7zVqTALMRNNoo=zca-H98HDVvB_A@mail.gmail.com>
Subject: Re: Sometimes unusable i2c-hid devices in 4.17-rcX
To:     Mario.Limonciello@dell.com
Cc:     Jason Gerecke <killertofu@gmail.com>,
        linux-input <linux-input@vger.kernel.org>,
        linux-kernel@vger.kernel.org
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Sender: linux-kernel-owner@vger.kernel.org
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On Tue, May 29, 2018 at 10:56 PM <Mario.Limonciello@dell.com> wrote:
>
> > -----Original Message-----
> > From: Benjamin Tissoires [mailto:benjamin.tissoires@gmail.com]
> > Sent: Thursday, May 24, 2018 8:57 AM
> > To: Limonciello, Mario; Jason Gerecke
> > Cc: linux-input; linux-kernel@vger.kernel.org
> > Subject: Re: Sometimes unusable i2c-hid devices in 4.17-rcX
> >
> > Hi Mario,
> >
> > On Tue, May 22, 2018 at 6:15 PM,  <Mario.Limonciello@dell.com> wrote:
> > > Benjamin,
> > >
> > >> -----Original Message-----
> > >> From: Benjamin Tissoires [mailto:benjamin.tissoires@gmail.com]
> > >> Sent: Friday, May 18, 2018 1:18 PM
> > >> To: Limonciello, Mario
> > >> Cc: linux-input; linux-kernel@vger.kernel.org
> > >> Subject: Re: Sometimes unusable i2c-hid devices in 4.17-rcX
> > >>
> > >> On Thu, May 17, 2018 at 4:44 PM,  <Mario.Limonciello@dell.com> wrote:
> > >> >> -----Original Message-----
> > >> >> From: Benjamin Tissoires [mailto:benjamin.tissoires@gmail.com]
> > >> >> Sent: Thursday, May 17, 2018 9:28 AM
> > >> >> To: Limonciello, Mario
> > >> >> Cc: linux-input; linux-kernel@vger.kernel.org
> > >> >> Subject: Re: Sometimes unusable i2c-hid devices in 4.17-rcX
> > >> >>
> > >> >> Hi Mario,
> > >> >>
> > >> >> On Wed, May 16, 2018 at 10:00 PM,  <Mario.Limonciello@dell.com> wrote:
> > >> >> > Hi All,
> > >> >> >
> > >> >> > I've been running 4.16-rc7 on an XPS 9365 for some time and recently
> > moved
> > >> up
> > >> >> to 4.17-rc5.
> > >> >> > Immediately I noticed that i2c-hid devices (both touchscreen and touchpad)
> > >> were
> > >> >> not working.
> > >> >> > Also when shutting the system down or rebooting it would just hang. (magic
> > >> sysrq
> > >> >> still worked).
> > >> >> >
> > >> >> > I figured it was an easy to identify regression so I started a bisect but it
> > came
> > >> up
> > >> >> with garbage
> > >> >> > that ended in selftests shortly after 4.17-rc2.  I realized that's because is still
> > >> will
> > >> >> fail on 4.17-rc2
> > >> >> > occasionally, seemingly after trying something newer and warm rebooting.
> > >> >> > So it seems like it's "worse" after 4.17-rc2 (doesn't work at all) but semi
> > >> >> reproducible on 4.17-rc2.
> > >> >> >
> > >> >> > Not sure if I'm chasing some initialization race, but wanted to see if anyone
> > >> else
> > >> >> was running into this
> > >> >> > or has some ideas?
> > >> >>
> > >> >> I am reliably running a v4.17-rc3 with a merge on Jiri's tree on the 9360.
> > >> >>
> > >> >> I doubt it's related to the event processing as I am not encountering
> > >> >> those issues.
> > >> >>
> > >> >> It *could* be related to the interrupts not being properly raised.
> > >> >>
> > >> >> Could you monitor /proc/interrupts and check if the ones associated
> > >> >> with your i2c-hid devices are increasing when you are using them?
> > >> >> Also, does the device emits raw HID events? (you can use hid-recorder
> > >> >> to check on the hidraw nodes.)
> > >> >
> > >>
> > >> Sorry, I couldn't get to it today. Monday is a public holiday here, so
> > >> I'll check on this Tuesday.
> > >>
> > >> > I checked both, /proc/interrupts isn't incrementing at all with the DLL077A:01
> > >> device.
> > >> > Hid-recorder is showing output from the raw HID node.
> > >>
> > >> I don't really understand how the hidraw node can send data while the
> > >> interrupts are not raised.
> > >>
> > >> Could you share the output of hid-recorder?
> > > Sure attached.
> > > Note that I had a dock connected at the same time since I needed power.  This
> > was
> > > different than my previous tests.
> > > That dock has 2 HID endpoints (so that might muddy this, I can re-capture if you
> > need me to)
> >
> > According to the file, this is the touchpad, and you draw a quick
> > circle on it. It's surprising the interrupts are not incrementing
> > because it clearly works fine.
> >
> > >
> > >>
> > >> >
> > >> > Same thing for the touchscreen, no incrementing for it on the
> > i2c_designware.0
> > >> device.
> > >> >
> > >> > Something notable however;
> > >> > When in this bad state hid-recorder didn't show /dev/hidraw1 for the
> > >> touchscreen (which
> > >> > Happens to be a Wacom touch screen).
> > >> > It only showed /dev/hidraw0 for the touchpad.
> > >>
> > >> This explains why the touchscreen doesn't increment the interrupts.
> > >> Something I missed in the first email is that the hidraw0 node
> > >> disappear for the wacom device as the touchpad gets the hidraw0 name.
> > >>
> > >> Could you provide the output  of a working kernel configuration of:
> > >> sudo hid-recorder /dev/hidraw*
> > >>
> > >> This should provide me the whole logs at the same time of all the
> > >> hidraw nodes, and will allow me to reproduce the combination of
> > >> wacom/hid-multitouch you are experiencing.
> > >>
> > > I was having a hard time getting it to work again with 4.17-rcX while trying
> > > to capture this.
> > > The only thing I got it to work with was when I turned off the touchscreen
> > > In FW setup.
> >
> > Yeah. Sorry I should have been more precise. Ideally, could you try to
> > capture all the hidraw nodes at once on a working kernel (4.16 or
> > 4.15)?
> > I shouldn't need the current broken behavior, just a description (with
> > some events) of the devices as they are supposed to be working.
> >
>
> Yes, here you go.  This is with me touching both touchscreen and touchpad.
> It's on Ubuntu's 4.15.

Thanks a lot for the logs.

I think I found it. It's a combination of two bugs actually:
- the first one is a race when we load hid-multitouch and wacom in
parallel. Both drivers will call __hid_bus_driver_added() which will
reprobe the devices if they are still marked as handled by
hid-generic. However, the test appears to not be concurrent safe so we
are rebinding twice the wacom device (one after loading wacom.ko, and
one after loading hid-multitouch.ko)
- the second issue is one we came to realize a few days ago with
Richard Hughes. The wacom driver suffers from a bug in power_supply
where you can not unbind it right after having bound it, because
power_supply_unregister() wait for the completion of its init work
which takes teh lock on the device. However, when you unbind a driver,
the lock is already help, so you have a dead lock.

I am not sure I'll found a solution for the second issue right now. I
can't reproduce it locally with my test kernel :(
For the first solution, it should be easy enough to add a locking
mechanism to be sure we are not unibinding twice the device.

Note that if we hadn't the second issue, the first one would only show
dmesg logs, but the device would be working :/

Cheers,
Benjamin

>
> > >
> > > So I guess that means it's probably something Wacom race condition on
> > > initialization since you noted the hidraw endpoint getting clobbered.
> >
> > Still, it's curious the wacom module disappear without any message.
> > Jason, did you experienced such issues with some of the integrated
> > wacom panels on v4.17-rc3 and later?
> >
> > Cheers,
> > Benjamin
> >
> > >> >> >
> > >> >> > #dmesg | grep 'i2c\|hid' doesn't show any obvious errors when in this state
> > of
> > >> >> non functional hid stuff.
> > >> >> > [    2.398649] i2c /dev entries driver
> > >> >> > [    2.881651] hidraw: raw HID events driver (C) Jiri Kosina
> > >> >> > [    3.683583] ish-hid {33AECD58-B679-4E54-9BD9-A04D34F0C226}: [hid-
> > ish]:
> > >> >> enum_devices_done OK, num_hid_devices=5
> > >> >> > [    3.701259] hid-generic 001F:8086:22D8.0001: hidraw0: <UNKNOWN>
> > HID
> > >> >> v2.00 Device [hid-ishtp 8086:22D8] on
> > >> >> > [    3.702204] hid-generic 001F:8086:22D8.0002: hidraw1: <UNKNOWN>
> > HID
> > >> >> v2.00 Device [hid-ishtp 8086:22D8] on
> > >> >> > [    3.703063] hid-generic 001F:8086:22D8.0003: hidraw2: <UNKNOWN>
> > HID
> > >> >> v2.00 Device [hid-ishtp 8086:22D8] on
> > >> >> > [    3.704276] hid-generic 001F:8086:22D8.0004: hidraw3: <UNKNOWN>
> > HID
> > >> >> v2.00 Device [hid-ishtp 8086:22D8] on
> > >> >> > [    3.704557] hid-generic 001F:8086:22D8.0005: hidraw4: <UNKNOWN>
> > HID
> > >> >> v2.00 Device [hid-ishtp 8086:22D8] on
> > >> >> > [    3.750710] psmouse serio1: synaptics: Your touchpad (PNP: DLL077a
> > >> PNP0f13)
> > >> >> says it can support a different bus. If i2c-hid and hid-rmi are not used, you
> > might
> > >> >> want to try setting psmouse.synaptics_intertouch to 1 and report this to
> > linux-
> > >> >> input@vger.kernel.org.
> > >> >> > [    7.030446] acpi INT33D5:00: intel-hid: created platform device
> > >> >> > [    7.199178] i2c_hid i2c-WCOM482F:00: i2c-WCOM482F:00 supply vdd not
> > >> >> found, using dummy regulator
> > >> >> > [    7.246638] input: WCOM482F:00 056A:482F as
> > >> >> /devices/pci0000:00/0000:00:15.0/i2c_designware.0/i2c-6/i2c-
> > >> >> WCOM482F:00/0018:056A:482F.0006/input/input11
> > >> >> > [    7.246873] hid-generic 0018:056A:482F.0006: input,hidraw0: I2C HID
> > v1.00
> > >> >> Mouse [WCOM482F:00 056A:482F] on i2c-WCOM482F:00
> > >> >> > [    7.275279] i2c_hid i2c-DLL077A:01: i2c-DLL077A:01 supply vdd not
> > found,
> > >> >> using dummy regulator
> > >> >> > [    7.304107] input: DLL077A:01 06CB:76AF as
> > >> >> /devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-7/i2c-
> > >> >> DLL077A:01/0018:06CB:76AF.0007/input/input14
> > >> >> > [    7.304212] hid-generic 0018:06CB:76AF.0007: input,hidraw1: I2C HID
> > v1.00
> > >> >> Mouse [DLL077A:01 06CB:76AF] on i2c-DLL077A:01
> > >> >> > [    7.657123] usbcore: registered new interface driver usbhid
> > >> >> > [    7.657124] usbhid: USB HID core driver
> > >> >> > [    7.722876] input: Wacom HID 482F Pen as
> > >> >> /devices/pci0000:00/0000:00:15.0/i2c_designware.0/i2c-6/i2c-
> > >> >> WCOM482F:00/0018:056A:482F.0006/input/input15
> > >> >> > [    7.723148] input: Wacom HID 482F Finger as
> > >> >> /devices/pci0000:00/0000:00:15.0/i2c_designware.0/i2c-6/i2c-
> > >> >> WCOM482F:00/0018:056A:482F.0006/input/input16
> > >> >> > [    7.723611] wacom 0018:056A:482F.0006: hidraw0: I2C HID v1.00 Mouse
> > >> >> [WCOM482F:00 056A:482F] on i2c-WCOM482F:00
> > >> >> > [    7.768275] input: DLL077A:01 06CB:76AF Touchpad as
> > >> >> /devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-7/i2c-
> > >> >> DLL077A:01/0018:06CB:76AF.0007/input/input19
> > >> >> > [    7.864201] hid-multitouch 0018:06CB:76AF.0007: input,hidraw0: I2C HID
> > >> v1.00
> > >> >> Mouse [DLL077A:01 06CB:76AF] on i2c-DLL077A:01
> > >> >> >
> > >> >> > However in this state, I can't rmmod i2c-hid.  It just hangs the system with
> > this
> > >> >> trace:
> > >> >> > [  243.033779] INFO: task kworker/u8:0:6 blocked for more than 120
> > seconds.
> > >> >> > [  243.033793]       Not tainted 4.17.0-rc1+ #37
> > >> >> > [  243.033798] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> > disables
> > >> this
> > >> >> message.
> > >> >> > [  243.033804] kworker/u8:0    D    0     6      2 0x80000000
> > >> >> > [  243.033826] Workqueue: events_power_efficient
> > >> >> power_supply_deferred_register_work
> > >> >> > [  243.033832] Call Trace:
> > >> >> > [  243.033850]  __schedule+0x3c2/0x890
> > >> >> > [  243.033861]  ? __switch_to_asm+0x40/0x70
> > >> >> > [  243.033868]  schedule+0x36/0x80
> > >> >> > [  243.033875]  schedule_preempt_disabled+0xe/0x10
> > >> >> > [  243.033882]  __mutex_lock.isra.4+0x2ae/0x4e0
> > >> >> > [  243.033890]  ? __switch_to_asm+0x34/0x70
> > >> >> > [  243.033899]  ? __switch_to_asm+0x40/0x70
> > >> >> > [  243.033906]  ? __switch_to_asm+0x40/0x70
> > >> >> > [  243.033914]  __mutex_lock_slowpath+0x13/0x20
> > >> >> > [  243.033920]  ? __mutex_lock_slowpath+0x13/0x20
> > >> >> > [  243.033927]  mutex_lock+0x2f/0x40
> > >> >> > [  243.033933]  power_supply_deferred_register_work+0x2b/0x50
> > >> >> > [  243.033944]  process_one_work+0x148/0x3d0
> > >> >> > [  243.033952]  worker_thread+0x4b/0x460
> > >> >> > [  243.033960]  kthread+0x102/0x140
> > >> >> > [  243.033967]  ? rescuer_thread+0x380/0x380
> > >> >> > [  243.033973]  ? kthread_associate_blkcg+0xa0/0xa0
> > >> >> > [  243.033982]  ret_from_fork+0x35/0x40
> > >> >> > [  243.034012] INFO: task systemd-udevd:308 blocked for more than 120
> > >> seconds.
> > >> >> > [  243.034018]       Not tainted 4.17.0-rc1+ #37
> > >> >> > [  243.034022] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> > disables
> > >> this
> > >> >> message.
> > >> >> > [  243.034027] systemd-udevd   D    0   308    279 0x80000104
> > >> >> > [  243.034033] Call Trace:
> > >> >> > [  243.034041]  __schedule+0x3c2/0x890
> > >> >> > [  243.034049]  schedule+0x36/0x80
> > >> >> > [  243.034056]  schedule_timeout+0x1e7/0x360
> > >> >> > [  243.034066]  ? ttwu_do_activate+0x77/0x80
> > >> >> > [  243.034074]  wait_for_completion+0xb4/0x140
> > >> >> > [  243.034082]  ? wake_up_q+0x70/0x70
> > >> >> > [  243.034090]  flush_work+0x12a/0x1e0
> > >> >> > [  243.034097]  ? worker_detach_from_pool+0xb0/0xb0
> > >> >> > [  243.034107]  __cancel_work_timer+0x112/0x190
> > >> >> > [  243.034116]  cancel_delayed_work_sync+0x13/0x20
> > >> >> > [  243.034122]  power_supply_unregister+0x37/0xb0
> > >> >> > [  243.034127]  devm_power_supply_release+0x11/0x20
> > >> >> > [  243.034135]  release_nodes+0x107/0x1f0
> > >> >> > [  243.034147]  devres_release_group+0x7c/0xb0
> > >> >> > [  243.034162]  wacom_remove+0xce/0x120 [wacom]
> > >> >> > [  243.034178]  hid_device_remove+0x4d/0xa0 [hid]
> > >> >> > [  243.034187]  device_release_driver_internal+0x155/0x220
> > >> >> > [  243.034198]  ? __hid_bus_driver_added+0x40/0x40 [hid]
> > >> >> > [  243.034208]  ? hid_destroy_device+0x60/0x60 [hid]
> > >> >> > [  243.034215]  device_release_driver+0x12/0x20
> > >> >> > [  243.034221]  device_reprobe+0x30/0x50
> > >> >> > [  243.034231]  __hid_bus_reprobe_drivers+0x45/0x50 [hid]
> > >> >> > [  243.034239]  bus_for_each_dev+0x64/0xb0
> > >> >> > [  243.034250]  __hid_bus_driver_added+0x2c/0x40 [hid]
> > >> >> > [  243.034256]  bus_for_each_drv+0x67/0xb0
> > >> >> > [  243.034267]  __hid_register_driver+0x6f/0x80 [hid]
> > >> >> > [  243.034275]  ? 0xffffffffc07f5000
> > >> >> > [  243.034287]  mt_driver_init+0x23/0x1000 [hid_multitouch]
> > >> >> > [  243.034296]  do_one_initcall+0x4f/0x1ce
> > >> >> > [  243.034303]  ? _cond_resched+0x1a/0x50
> > >> >> > [  243.034315]  ? kmem_cache_alloc_trace+0xb8/0x1f0
> > >> >> > [  243.034327]  do_init_module+0x5f/0x219
> > >> >> > [  243.034335]  load_module+0x24c7/0x2be0
> > >> >> > [  243.034348]  __do_sys_finit_module+0xe5/0x120
> > >> >> > [  243.034354]  ? __do_sys_finit_module+0xe5/0x120
> > >> >> > [  243.034363]  __x64_sys_finit_module+0x1a/0x20
> > >> >> > [  243.034370]  do_syscall_64+0x54/0x110
> > >> >> > [  243.034380]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
> > >> >> > [  243.034386] RIP: 0033:0x7f2ec539c839
> > >> >> > [  243.034390] RSP: 002b:00007ffcfc620298 EFLAGS: 00000246 ORIG_RAX:
> > >> >> 0000000000000139
> > >> >> > [  243.034396] RAX: ffffffffffffffda RBX: 000055d6a0147ec0 RCX:
> > >> >> 00007f2ec539c839
> > >> >> > [  243.034399] RDX: 0000000000000000 RSI: 00007f2ec507b0e5 RDI:
> > >> >> 000000000000000f
> > >> >> > [  243.034402] RBP: 00007f2ec507b0e5 R08: 0000000000000000 R09:
> > >> >> 00007ffcfc6203b0
> > >> >> > [  243.034405] R10: 000000000000000f R11: 0000000000000246 R12:
> > >> >> 0000000000000000
> > >> >> > [  243.034408] R13: 000055d6a017b3a0 R14: 0000000000020000 R15:
> > >> >> 000055d6a0147ec0
> > >> >> > --
> > >> >> > To unsubscribe from this list: send the line "unsubscribe linux-input" in
> > >> >> > the body of a message to majordomo@vger.kernel.org
> > >> >> > More majordomo info at  http://vger.kernel.org/majordomo-info.html