e48eb085ac
The belkin_sa module has a problem coping with a 0 return from tty_get_baud_rate() -- the subsequent BELKIN_SA_BAUD macro drivers/usb/serial/belkin_sa.h:#define BELKIN_SA_BAUD(b) (230400/b) performs a divide with it leading to the following divide error: usb 3-1: Belkin / Peracom / GoHubs USB Serial Adapter converter now attached to ttyUSB0 PM: Adding info for No Bus:usbdev3.3_ep81 PM: Adding info for No Bus:usbdev3.3_ep01 PM: Adding info for No Bus:usbdev3.3_ep82 divide error: 0000 [#1] SMP Modules linked in: vfat fat iwl3945 mac80211 cfg80211 belkin_sa usbserial usb_storage autofs4 vmnet(P) vmmon(P) aes nf_conntrack_netbios_ns ipt_REJECT nf_conntrack_ipv4 xt_state nf_conntrack nfnetlink xt_tcpudp iptable_filter ip_tables x_tables cpufreq_ondemand acpi_cpufreq video output sbs button dock battery ac arc4 snd_hda_intel ecb blkcipher snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss sr_mod snd_mixer_oss rtc_cmos cdrom iTCO_wdt iTCO_vendor_support snd_pcm rtc_core snd_timer serio_raw b44 ssb rtc_lib parport ata_piix snd soundcore snd_page_alloc mii ata_generic sg ahci libata sd_mod scsi_mod ext3 jbd mbcache ehci_hcd ohci_hcd uhci_hcd CPU: 1 EIP: 0060:[<f8dd1747>] Tainted: P VLI EFLAGS: 00010246 (2.6.23-rc1 #1) EIP is at belkin_sa_set_termios+0x18e/0x5b9 [belkin_sa] eax: 00038400 ebx: 00000000 ecx: 00000000 edx: 00000000 esi: 00038400 edi: 00001cb2 ebp: de49adb0 esp: de49ad6c ds: 007b es: 007b fs: 00d8 gs: 0033 ss: 0068 Process minicom (pid: 7306, ti=de49a000 task=eed6c3b0 task.ti=de49a000) Stack: d85c74f0 00000046 00000002 00000001 d85c74f0 d85c74f0 00000246 c887c658 00000001 00000cb0 00000001 00000084 00000000 d01b58c0 f6ba10e0 de49ade8 de49ae40 de49add0 f8e2526b d85c74b8 ca6e6dbc de49ae40 d85c746c eded72e8 Call Trace: [<c0405f35>] show_trace_log_lvl+0x1a/0x2f [<c0405fe5>] show_stack_log_lvl+0x9b/0xa3 [<c04061a5>] show_registers+0x1b8/0x289 [<c0406389>] die+0x113/0x246 [<c0622f98>] do_trap+0x8a/0xa3 [<c04068dc>] do_divide_error+0x85/0x8f [<c0622d6a>] error_code+0x72/0x78 [<f8e2526b>] serial_set_termios+0x86/0x8d [usbserial] [<c0542d33>] set_termios+0x309/0x34c [<c0542ece>] n_tty_ioctl+0x158/0x4ba [<c054030b>] tty_ioctl+0xc78/0xcd6 [<c048aea0>] do_ioctl+0x50/0x67 [<c048b100>] vfs_ioctl+0x249/0x25c [<c048b15c>] sys_ioctl+0x49/0x61 [<c0404ed2>] sysenter_past_esp+0x5f/0x99 ======================= Code: 85 c0 79 14 c7 44 24 04 67 1c dd f8 c7 04 24 d4 1e dd f8 e8 96 99 65 c7 8b 46 04 be 00 84 03 00 e8 47 11 77 c7 31 d2 89 c1 89 f0 <f7> f1 66 85 c0 89 c1 b8 01 00 00 00 0f 44 c8 8b 45 d8 85 db 8b EIP: [<f8dd1747>] belkin_sa_set_termios+0x18e/0x5b9 [belkin_sa] SS:ESP 0068:de49ad6c The small patch below should take care of this situation. Note that my kernel was tainted (vmware) but the problem will occur if tty_get_baud_rate() ever returns zero and should be taken care of. Signed-off-by: Andy Green <andy@warmcat.com> Cc: William Greathouse <wgreathouse@smva.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: stable <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
To understand all the Linux-USB framework, you'll use these resources:
* This source code. This is necessarily an evolving work, and
includes kerneldoc that should help you get a current overview.
("make pdfdocs", and then look at "usb.pdf" for host side and
"gadget.pdf" for peripheral side.) Also, Documentation/usb has
more information.
* The USB 2.0 specification (from www.usb.org), with supplements
such as those for USB OTG and the various device classes.
The USB specification has a good overview chapter, and USB
peripherals conform to the widely known "Chapter 9".
* Chip specifications for USB controllers. Examples include
host controllers (on PCs, servers, and more); peripheral
controllers (in devices with Linux firmware, like printers or
cell phones); and hard-wired peripherals like Ethernet adapters.
* Specifications for other protocols implemented by USB peripheral
functions. Some are vendor-specific; others are vendor-neutral
but just standardized outside of the www.usb.org team.
Here is a list of what each subdirectory here is, and what is contained in
them.
core/ - This is for the core USB host code, including the
usbfs files and the hub class driver ("khubd").
host/ - This is for USB host controller drivers. This
includes UHCI, OHCI, EHCI, and others that might
be used with more specialized "embedded" systems.
gadget/ - This is for USB peripheral controller drivers and
the various gadget drivers which talk to them.
Individual USB driver directories. A new driver should be added to the
first subdirectory in the list below that it fits into.
image/ - This is for still image drivers, like scanners or
digital cameras.
input/ - This is for any driver that uses the input subsystem,
like keyboard, mice, touchscreens, tablets, etc.
media/ - This is for multimedia drivers, like video cameras,
radios, and any other drivers that talk to the v4l
subsystem.
net/ - This is for network drivers.
serial/ - This is for USB to serial drivers.
storage/ - This is for USB mass-storage drivers.
class/ - This is for all USB device drivers that do not fit
into any of the above categories, and work for a range
of USB Class specified devices.
misc/ - This is for all USB device drivers that do not fit
into any of the above categories.