Bug 443986

Summary: WARNING: at drivers/usb/serial/usb-serial.c:311 serial_write+0x6a/0x89 [usbserial]()
Product: [openSUSE] openSUSE 11.1 Reporter: Felix Möller <felix>
Component: KernelAssignee: E-mail List <kernel-maintainers>
Status: RESOLVED WONTFIX QA Contact: E-mail List <qa-bugs>
Severity: Normal    
Priority: P5 - None CC: jreuter
Version: Factory   
Target Milestone: ---   
Hardware: Other   
OS: Other   
Whiteboard:
Found By: --- Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---

Description Felix Möller 2008-11-11 23:20:37 UTC 
Plugging in my new Holux M-241 I get the following when starting gpsd (at least sometimes ;))

cp2101: Silicon Labs CP2101/CP2102 RS232 serial adaptor driver v0.07
------------[ cut here ]------------
WARNING: at drivers/usb/serial/usb-serial.c:324 serial_write_room+0x4f/0x62 [usbserial]()
Modules linked in: cp2101 usbserial aes_i586 aes_generic af_packet i915 drm snd_pcm_oss snd_mixer_oss snd_seq binfmt_misc snd_seq_device edd ipv6 cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq speedstep_lib microcode fuse loop dm_mod arc4 ecb crypto_blkcipher snd_hda_intel uvcvideo thermal snd_pcm joydev ath5k compat_ioctl32 snd_timer processor iTCO_wdt video videodev v4l1_compat snd_page_alloc ohci1394 mac80211 snd_hwdep iTCO_vendor_support appletouch sr_mod thermal_sys led_class ieee1394 i2c_i801 intel_agp sky2 rtc_cmos output isight_firmware hwmon button ac pcspkr battery cdrom snd agpgart rtc_core cfg80211 i2c_core rtc_lib soundcore sg usbhid hid ff_memless ehci_hcd sd_mod uhci_hcd crc_t10dif usbcore ext3 mbcache jbd ata_piix libata scsi_mod dock
Supported: No
Pid: 7, comm: events/0 Tainted: G          2.6.27.5-1-default #1
 [<c0106620>] dump_trace+0x6b/0x249        
 [<c0107155>] show_trace+0x20/0x39     
 [<c034a4f5>] dump_stack+0x71/0x76      
 [<c012b3e0>] warn_on_slowpath+0x4d/0x70   
 [<f91014e9>] serial_write_room+0x4f/0x62 [usbserial]
 [<c0290cf4>] tty_write_room+0x15/0x16     
 [<c028f12a>] opost+0xf/0x1ad     
 [<c02905f8>] n_tty_receive_buf+0x2d3/0x8f9                                  
 [<c028c060>] flush_to_ldisc+0xff/0x19d 
 [<c01396c0>] run_workqueue+0x9f/0x13e                               
 [<c0139815>] worker_thread+0xb6/0xc2                             
 [<c013c5c6>] kthread+0x38/0x5d                                
 [<c0106177>] kernel_thread_helper+0x7/0x10                        
 =======================         
---[ end trace 10c895dbaa1bc7a6 ]---

this is:
macbook:/home/fm # uname -a
Linux macbook 2.6.27.5-1-default #1 SMP 2008-11-08 04:59:08 +0100 i686 i686 i386 GNU/Linux
Comment 1 Felix Möller 2008-11-11 23:24:44 UTC 
maybe this is bug #423496
Comment 2 Joerg Reuter 2008-11-19 00:31:59 UTC 
I suspect gpsd is partly to blame here. I'll take a look at gpsd, this apparently happens when a user space process closes the port with data still due to be written (kernel-maintainers, is that correct?) and I'm curious why gpsd is closing the port at all (in one case I know why. It segfaulted. Ouch.)
Comment 3 Greg Kroah-Hartman 2008-11-19 15:49:35 UTC 
These warnings are harmless and can be ignored.  A check was added to the kernel to test for this kind of problem, and it turns out it is quite common.  It has been resolved in future kernel releases (2.6.28), but is too intrusive to be backported to 2.6.27.

So this can be safely ignored.