[opensuse] USB device can't reliable unplugged
Since two month I own a WinTV soloHD television USB stick. The chipset is em28178, which is supported by the kernel modules em28xx, em28xx_dvb and em28xx_rc. I tested different kernels, now 4.9.8-1.gaf90696-default from Kernel_stable repository. The card works perfectly, but often the Kernel crashes if the device is unplugged. Unfortunately I can't see any OOPS message, if the system freezes during unplugging. Is there any trick to get the Kernel messages, so that I can write a Kernel bug report? On the other hand there is no direct need to unplug the USB device. But the USB device does not survive a hibernate/resume cycle and I like to use hibernate/resume. Unloading the driver in /usr/lib/systemd/system-sleep/98-tv.sh does not reliable work. The Kernel freezes often before hibernation. It's the same, if I make the "modprobe" calls in the shell. "rcmythbackend" is the systemd job for MythTV. The TV card is used by MythTV and I stop MythTV before unloading the USB em28xx* modules. #!/bin/bash case "$1/$2" in pre/*) echo "Going to $2..." /usr/sbin/rcmythbackend stop sleep 4 /usr/sbin/modprobe -v -r em28xx-dvb sleep 1 /usr/sbin/modprobe -v -r em28xx_rc ;; post/*) echo "Waking up from $2..." sleep 2 /usr/sbin/modprobe -v em28xx_rc /usr/sbin/modprobe -v em28xx-dvb sleep 5 /usr/sbin/rcmythbackend start ;; *) echo "Unknown sleep command $1/$2..." ;; esac Any ideas how to resolve such USB problems correctly? Regards, Björn -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2017-02-06 14:03, Bjoern Voigt wrote:
Since two month I own a WinTV soloHD television USB stick. The chipset is em28178, which is supported by the kernel modules em28xx, em28xx_dvb and em28xx_rc. I tested different kernels, now 4.9.8-1.gaf90696-default from Kernel_stable repository.
The card works perfectly, but often the Kernel crashes if the device is unplugged.
Unfortunately I can't see any OOPS message, if the system freezes during unplugging. Is there any trick to get the Kernel messages, so that I can write a Kernel bug report?
Well, the first thing to try is to switch to text mode (ctrl-alt-F10) to see the log there, and then attempt to unplug the device. Hopefully you get some messages and can take a photo with a camera. If you have a real hardware serial port (rs232) you can tell the kernel to dump messages there, and capture them on another computer; this one may use an usb-rs232 converter. If not, another method is to tell the kernel to send the message via ethernet port to another computer in the LAN. If you are going to use any of that, I can try dig out my notes and give you more info. I have done both methods, but not recently. It is not point and shoot, unfortunately. -- Cheers / Saludos, Carlos E. R. (from 42.2 x86_64 "Malachite" at Telcontar)
Carlos E. R. wrote:
Well, the first thing to try is to switch to text mode (ctrl-alt-F10) to see the log there, and then attempt to unplug the device. Hopefully you get some messages and can take a photo with a camera.
If you have a real hardware serial port (rs232) you can tell the kernel to dump messages there, and capture them on another computer; this one may use an usb-rs232 converter.
If not, another method is to tell the kernel to send the message via ethernet port to another computer in the LAN.
If you are going to use any of that, I can try dig out my notes and give you more info. I have done both methods, but not recently. It is not point and shoot, unfortunately. Thanks for the hints. Especially the console 10 hint was useful.
One problem with console 10 is, that the Kernel crashes became more unlikely in console 10 compared with crashes when using the X11 display. In X11 the Kernel often crashed, if I unplugged the unused USB DVB device. In console 10 I had to use the device heavily (recording a TV show), until the Kernel crashed reliable every-time I unplugged the USB device. Here is my bug report, if someone is interested: Bug 194171 - em28xx DVB-T2 USB card can't be unplugged and fails to hibernate/resume https://bugzilla.kernel.org/show_bug.cgi?id=194171 I found, that my mainboard has a serial port, but it's not connected to the front or back panel and so currently useless. Greetings, Björn -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2017-02-06 21:21, Bjoern Voigt wrote:
Carlos E. R. wrote:
Thanks for the hints. Especially the console 10 hint was useful.
One problem with console 10 is, that the Kernel crashes became more unlikely in console 10 compared with crashes when using the X11 display. In X11 the Kernel often crashed, if I unplugged the unused USB DVB device. In console 10 I had to use the device heavily (recording a TV show), until the Kernel crashed reliable every-time I unplugged the USB device.
Well, that also hints to the problem being related to something the desktop does.
I found, that my mainboard has a serial port, but it's not connected to the front or back panel and so currently useless.
Ah, same here; but I connected a cable to it and have it available. I reused an old connector I had from a much older box, but I had to add wires to it, it was too short for this board and box. This port is the most reliable method for obtaining kernel messages during a crash, because it is very low level and doesn't need divers or layers that may already have crashed. -- Cheers / Saludos, Carlos E. R. (from 42.2 x86_64 "Malachite" at Telcontar)
participants (2)
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Bjoern Voigt
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Carlos E. R.