I have the following modem:
Bus 002 Device 025: ID 12d1:1436 Huawei Technologies Co., Ltd.
When I plug it in, it works normally. After some time, usually 10-300 min. it starts to give the errors.
Code:
[ 322.332390] usb 2-1.1: new high-speed USB device number 25 using ehci_hcd
[ 322.426603] usb 2-1.1: New USB device found, idVendor=12d1, idProduct=1436
[ 322.426607] usb 2-1.1: New USB device strings: Mfr=4, Product=3, SerialNumber=0
[ 322.426610] usb 2-1.1: Product: HUAWEI Mobile
[ 322.426612] usb 2-1.1: Manufacturer: HUAWEI Technology
[ 322.429359] option 2-1.1:1.0: GSM modem (1-port) converter detected
[ 322.429464] usb 2-1.1: GSM modem (1-port) converter now attached to ttyUSB0
[ 322.431171] cdc_ether 2-1.1:1.1: wwan0: register 'cdc_ether' at usb-0000:00:1d.0-1.1, Mobile Broadband Network Device, 02:50:f3:00:00:00
[ 322.431428] option 2-1.1:1.3: GSM modem (1-port) converter detected
[ 322.431516] usb 2-1.1: GSM modem (1-port) converter now attached to ttyUSB1
[ 322.431616] option 2-1.1:1.4: GSM modem (1-port) converter detected
[ 322.431675] usb 2-1.1: GSM modem (1-port) converter now attached to ttyUSB2
[ 322.432001] scsi30 : usb-storage 2-1.1:1.5
[ 322.432544] scsi31 : usb-storage 2-1.1:1.6
[ 323.430875] scsi 30:0:0:0: CD-ROM HUAWEI Mass Storage 2.31 PQ: 0 ANSI: 2
[ 323.431750] scsi 31:0:0:0: Direct-Access HUAWEI SD Storage 2.31 PQ: 0 ANSI: 2
[ 323.434163] sr1: scsi-1 drive
[ 323.434390] sr 30:0:0:0: Attached scsi CD-ROM sr1
[ 323.438349] sd 31:0:0:0: [sdh] Attached SCSI removable disk
[ 329.497548] PPP BSD Compression module registered
[ 329.517855] PPP Deflate Compression module registered
[ 332.842085] ip_tables: (C) 2000-2006 Netfilter Core Team
[ 332.860261] nf_conntrack version 0.5.0 (16384 buckets, 65536 max)
[ 770.048210] sr 30:0:0:0: Device offlined - not ready after error recovery
[ 770.059376] sr 30:0:0:0: rejecting I/O to offline device
[ 770.059389] sr 30:0:0:0: rejecting I/O to offline device
[ 772.223007] sr 30:0:0:0: rejecting I/O to offline device
[ 772.223020] sr 30:0:0:0: rejecting I/O to offline device
...(these errors repeat infinitely every ~2 seconds)...
sr1 is "cd-rom" with modem software, modem itself continues to function properly. I want to note that I did not have sr1 mounted anywhere. So, I do not understand why the kernel gives me these messages so frequently.
My question:
Is it possible to find out what makes the kernel to send "I/O to offline device" twice every two seconds? Perhaps frequent unnecessary I/O is the reason why modem gets confused. Also, these errors are very annoying, because they spam syslog and dmesg output.
My configuration: Supermicro X8SIE motherboard + Xeon X3450 + Registered ECC. At this moment I have the following kernel: Linux camn 3.3.0-trunk-amd64 #1 SMP (Debian). Previously I had 3.2 kernel on this computer and modem' behavior was the same.
I tried to Google - unfortunately found no similar problems, and I found no helpful information how to debug the problem like this to understand why the kernel tries to do something with virtual cd-rom twice every two seconds. I'm programmer, but have no experience in debugging the kernel-related problems, so I even can't tell for sure if this is hardware problem or kernel bug which needs to be reported. So I hope someone more knowledgeable in this area points me in right direction.
3G USB modem gives "rejecting I/O to offline device" errors
