Date: Thu, 13 Sep 2012 14:50:12 +0930 From: Benjamin Close <Benjamin.Close@clearchain.com> To: Hans Petter Selasky <hselasky@c2i.net> Cc: mav@freebsd.org, freebsd-usb@freebsd.org Subject: Re: Fwd: usb port issue in 9.1-Prerelease (Possibly Cam related) Message-ID: <50516D0C.6060501@clearchain.com> In-Reply-To: <201209120749.07628.hselasky@c2i.net> References: <504DED78.2010203@clearchain.com> <504FDD37.5060407@clearchain.com> <201209120749.07628.hselasky@c2i.net>
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Hi Folks,
It actually looks like a race condition. I've noticed over the last day
that *sometimes* it does do the right thing. The dmesg when it works is:
ugen3.2: <HUA WEI> at usbus3 (disconnected)
u3g0: at uhub3, port 2, addr 2 (disconnected)
umass0: at uhub3, port 2, addr 2 (disconnected)
(cd1:umass-sim0:0:0:0): lost device, 1 refs
(pass4:umass-sim0:0:0:0): passdevgonecb: devfs entry is gone
(cd1:umass-sim0:0:0:0): removing device entry
umass1: at uhub3, port 2, addr 2 (disconnected)
(da0:umass-sim1:1:0:0): lost device - 0 outstanding, 1 refs
(pass5:umass-sim1:1:0:0): passdevgonecb: devfs entry is gone
(da0:umass-sim1:1:0:0): removing device entry
The difference between this one and the one that fails is that the pass
adapters remove before the da/cd1 device.
ie when it works:
(cd1:umass-sim0:0:0:0): lost device, 1 refs
(pass4:umass-sim0:0:0:0): passdevgonecb: devfs entry is gone
(cd1:umass-sim0:0:0:0): removing device entry
When it doesn't:
(cd1:umass-sim0:0:0:0): lost device, 1 refs
(cd1:umass-sim0:0:0:0): removing device entry
(pass4:umass-sim0:0:0:0): passdevgonecb: devfs entry is gone
Cheers,
Benjamin
On 12/09/12 3:19 PM, Hans Petter Selasky wrote:
> Hi Alexander,
>
> Looks like some bugs in the refcounting in CAM layer.
>
> --HPS
>
> On Wednesday 12 September 2012 02:54:15 Benjamin Close wrote:
>> Sending to -usb as no response from -stable.
>>
>>
>> -------- Original Message --------
>> Subject: usb port issue in 9.1-Prerelease (Possibly Cam related)
>> Date: Mon, 10 Sep 2012 23:09:04 +0930
>> From: Benjamin Close <Benjamin.Close@clearchain.com>
>> To: freebsd-stable@freebsd.org
>>
>>
>>
>> Hi Folks,
>> I've facing an intermittent hang with a USB port which seems cam
>> related:
>>
>> Event's that happen are:
>>
>> o USB modem (HUAWEI E220) plugged into PC
>>
>> ugen3.2: <HUA WEI> at usbus3
>> u3g0: <3G Modem> on usbus3
>> u3g0: Found 3 ports.
>> umass0: <USB MASS STORAGE> on usbus3
>> umass0: SCSI over Bulk-Only; quirks = 0x0000
>> umass0:6:0:-1: Attached to scbus6
>> umass1: <USB MASS STORAGE> on usbus3
>> umass1: SCSI over Bulk-Only; quirks = 0x0000
>> umass1:7:1:-1: Attached to scbus7
>> cd1 at umass-sim0 bus 0 scbus6 target 0 lun 0
>> cd1: <HUAWEI Mass Storage 2.31> Removable CD-ROM SCSI-2 device
>> cd1: 1.000MB/s transfers
>> cd1: Attempt to query device size failed: NOT READY, Medium not present
>> da0 at umass-sim1 bus 1 scbus7 target 0 lun 0
>> da0: <HUAWEI SD Storage 2.31> Removable Direct Access SCSI-2 device
>> da0: 1.000MB/s transfers
>> da0: Attempt to query device size failed: NOT READY, Medium not present
>>
>>
>> o Time Elapses....many packets passed, no da0 or cd1 used.
>>
>>
>> o USB Modem drops off the bus
>> (It does this occasionally as it resets itself)
>>
>> o Causes USB bus to lose devices
>>
>> ugen3.2: <HUA WEI> at usbus3 (disconnected)
>> u3g0: at uhub3, port 1, addr 2 (disconnected)
>> (cd1:umass-sim0:0:0:0): lost device, 1 refs
>> (cd1:umass-sim0:0:0:0): removing device entry
>> (pass4:umass-sim0:0:0:0): passdevgonecb: devfs entry is gone
>> (da0:umass-sim1:1:0:0): lost device - 0 outstanding, 1 refs
>> (da0:umass-sim1:1:0:0): removing device entry
>> (pass5:umass-sim1:1:0:0): passdevgonecb: devfs entry is gone
>> umass0: at uhub3, port 1, addr 2 (disconnected)
>>
>>
>> At this point that particular USB port is effectively useless. Plugging
>> anything into the ports shows no device showing up.
>>
>> Running usbconfig hangs with:
>>
>> PID TID COMM TDNAME KSTACK
>> 48562 101874 usbconfig - mi_switch+0x186
>> sleepq_wait+0x42 _sx_xlock_hard+0x426 usbd_enum_lock+0xac
>> usb_ref_device+0x21c usb_open+0xc7 devfs_open+0x197 vn_open_cred+0x2ff
>> kern_openat+0x20a amd64_syscall+0x540 Xfast_syscall+0xf7
>>
>> Controller is:
>>
>> uhci0@pci0:0:26:0: class=0x0c0300 card=0x02091028 chip=0x28348086
>> rev=0x02 hdr=0x00
>> vendor = 'Intel Corporation'
>> device = '82801H (ICH8 Family) USB UHCI Controller'
>> class = serial bus
>> subclass = USB
>> uhci1@pci0:0:26:1: class=0x0c0300 card=0x02091028 chip=0x28358086
>> rev=0x02 hdr=0x00
>> vendor = 'Intel Corporation'
>> device = '82801H (ICH8 Family) USB UHCI Controller'
>> class = serial bus
>> subclass = USB
>> ehci0@pci0:0:26:7: class=0x0c0320 card=0x02091028 chip=0x283a8086
>> rev=0x02 hdr=0x00
>> vendor = 'Intel Corporation'
>> device = '82801H (ICH8 Family) USB2 EHCI Controller'
>> class = serial bus
>> subclass = USB
>>
>> It does however seem related to cam as looking at the various threads
>> for the usb hub I find:
>>
>> (kgdb) bt
>> #0 sched_switch (td=0xfffffe0002650000, newtd=0xfffffe000227f000,
>> flags=Variable "flags" is not available.
>> ) at /usr/src/sys/kern/sched_ule.c:1927
>> #1 0xffffffff808f34c6 in mi_switch (flags=260, newtd=0x0) at
>> /usr/src/sys/kern/kern_synch.c:485
>> #2 0xffffffff8092bfd2 in sleepq_wait (wchan=0xfffffe001ec2a900, pri=92)
>> at /usr/src/sys/kern/subr_sleepqueue.c:623
>> #3 0xffffffff808f3c69 in _sleep (ident=0xfffffe001ec2a900,
>> lock=0xfffffe00371e9210, priority=Variable "priority" is not available.
>> ) at /usr/src/sys/kern/kern_synch.c:250
>> #4 0xffffffff802bea02 in cam_sim_free (sim=0xfffffe001ec2a900,
>> free_devq=1) at /usr/src/sys/cam/cam_sim.c:112
>> #5 0xffffffff8074f8ba in umass_detach (dev=Variable "dev" is not
>> available. ) at /usr/src/sys/dev/usb/storage/umass.c:2183
>> #6 0xffffffff8091a054 in device_detach (dev=0xfffffe001ec2e900) at
>> device_if.h:214
>> #7 0xffffffff8075c458 in usb_detach_device (udev=0xfffffe0007ce8800,
>> iface_index=32 ' ', flag=Variable "flag" is not available.
>> ) at /usr/src/sys/dev/usb/usb_device.c:1065
>> #8 0xffffffff8075c5f4 in usb_unconfigure (udev=0xfffffe0007ce8800,
>> flag=Variable "flag" is not available.
>> ) at /usr/src/sys/dev/usb/usb_device.c:455
>> #9 0xffffffff8075c88e in usb_free_device (udev=0xfffffe0007ce8800,
>> flag=Variable "flag" is not available.
>> ) at /usr/src/sys/dev/usb/usb_device.c:2093
>> #10 0xffffffff80764e5e in uhub_explore (udev=0xfffffe0007353800) at
>> /usr/src/sys/dev/usb/usb_hub.c:358
>> #11 0xffffffff8074f536 in usb_bus_explore (pm=Variable "pm" is not
>> available.
>> ) at /usr/src/sys/dev/usb/controller/usb_controller.c:359
>> #12 0xffffffff80769173 in usb_process (arg=Variable "arg" is not available.
>> ) at /usr/src/sys/dev/usb/usb_process.c:170
>> #13 0xffffffff808bc2df in fork_exit (callout=0xffffffff807690a0
>> <usb_process>, arg=0xffffff80007c0e88, frame=0xffffff804743cc40) at
>> /usr/src/sys/kern/kern_fork.c:992
>> #14 0xffffffff80bc216e in fork_trampoline () at
>> /usr/src/sys/amd64/amd64/exception.S:602
>>
>>
>> From: cam_sim_free(struct cam_sim *sim, int free_devq)
>>
>> (kgdb) l
>> 107 {
>> 108 int error;
>> 109
>> 110 sim->refcount--;
>> 111 if (sim->refcount > 0) {
>>
>> 112 error = msleep(sim, sim->mtx, PRIBIO, "simfree",
>> 0);
>>
>> 113 KASSERT(error == 0, ("invalid error value for
>> msleep(9)"));
>> 114 }
>> 115
>> 116 KASSERT(sim->refcount == 0, ("sim->refcount == 0"));
>>
>>
>> It almost appears as if the cam layer is trying to finalise a write of
>> some sort but the physical device has already gone.
>>
>> (kgdb) p sim->refcount
>> $1 = 1
>>
>> Not sure why refcount is still ==1.
>>
>> The same device in a box running 9.0-Stable (as of about 3 months ago)
>> with a ICH9 controller works as expected.
>>
>> Any suggestions?
>>
>> Cheers,
>> Benjamin
>>
>>
>>
>>
>> _______________________________________________
>> freebsd-usb@freebsd.org mailing list
>> http://lists.freebsd.org/mailman/listinfo/freebsd-usb
>> To unsubscribe, send any mail to "freebsd-usb-unsubscribe@freebsd.org"
>
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