problem when testing with ttyUSB

[Okash Khawaja]

Hi,

I am testing Apollo and DoubleTalk LT using USB serial converter, so
over ttyUSB0. In the call to tty_open_by_driver I am passing in (188,0).
TTY opens without errors and ldsic is assigned too. But as soon as an
operation is called on the tty_struct, there is a general protection or
segmentation fault. Following is call trace from Apollo calling
speakup_tty->ops->write. Similar call trace results from ltlk calling
tty_write_room(speakup_tty) through spk_ttyio_synth_immediate.
Kernel version is 4.10 but i'm using the speakup code from
Greg K-H staging-next branch as that's what my patches apply to. Could
this be the problem?

I'm investigating it but any hints to speed it up will be helpful.

Thanks.

pr 01 12:54:29 sanghar kernel: speakup: loading out-of-tree module taints kernel.
Apr 01 12:54:29 sanghar kernel: speakup: module is from the staging directory, the quality is unknown, you have been warned.
Apr 01 12:54:29 sanghar kernel: input: Speakup as /devices/virtual/input/input19
Apr 01 12:54:29 sanghar kernel: initialized device: /dev/synth, node (MAJOR 10, MINOR 25)
Apr 01 12:54:29 sanghar kernel: speakup 3.1.6: initialized
Apr 01 12:54:29 sanghar kernel: synth name on entry is: (null)
Apr 01 12:54:34 sanghar kernel: speakup_apollo: module is from the staging directory, the quality is unknown, you have been warned.
Apr 01 12:54:34 sanghar kernel: synth probe
Apr 01 12:54:34 sanghar kernel: speakup: completed probe
Apr 01 12:54:34 sanghar kernel: speakup: Going to call tty->ops->write. tty->port=0x18571808
Apr 01 12:54:34 sanghar kernel: general protection fault: 0000 [#1] PREEMPT SMP
Apr 01 12:54:34 sanghar kernel: Modules linked in: speakup_apollo(CO) speakup(CO) ctr ccm joydev iTCO_wdt iTCO_vendor_support gpio_ich uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 arc4 videobuf2_core videodev iwldvm media dell_wmi sparse_keymap mac80211 dell_rbtn ppdev dell_laptop dell_smbios dcdbas dell_smm_hwmon coretemp kvm_intel snd_hda_codec_hdmi kvm iwlwifi cfg80211 snd_hda_codec_idt snd_hda_codec_generic irqbypass rfkill psmouse pcspkr i2c_i801 i915 lpc_ich cdc_ether usbnet mii pl2303 cdc_wdm cdc_acm usbserial snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep shpchp drm_kms_helper snd_pcm evdev snd_timer snd input_leds mousedev soundcore mac_hid thermal button battery drm e1000e wmi syscopyarea sysfillrect sysimgblt fb_sys_fops parport_pc i2c_algo_bit parport acpi_als ptp acpi_cpufreq pps_core
Apr 01 12:54:34 sanghar kernel:  tpm_tis tpm_tis_core kfifo_buf video intel_agp tpm intel_gtt industrialio ac sch_fq_codel ip_tables x_tables ext4 crc16 jbd2 fscrypto mbcache sr_mod cdrom sd_mod hid_generic usbhid hid uhci_hcd serio_raw atkbd libps2 sdhci_pci sdhci led_class ahci libahci libata scsi_mod firewire_ohci mmc_core firewire_core crc_itu_t ehci_pci ehci_hcd usbcore usb_common i8042 serio
Apr 01 12:54:34 sanghar kernel: CPU: 1 PID: 4806 Comm: speakup Tainted: G         C O    4.10.0-ARCH-00001-g6a2306b7d1e1-dirty #5
Apr 01 12:54:34 sanghar kernel: Hardware name: Dell Inc. Latitude E4300                  /0D201R, BIOS A13 10/29/2009
Apr 01 12:54:34 sanghar kernel: task: ffff880086c5c240 task.stack: ffffc900006f0000
Apr 01 12:54:34 sanghar kernel: RIP: 0010:serial_write+0x1d/0xa0 [usbserial]
Apr 01 12:54:34 sanghar kernel: RSP: 0018:ffffc900006f3dc8 EFLAGS: 00010282
Apr 01 12:54:34 sanghar kernel: RAX: ffffffffa065e082 RBX: ffffffffa065f000 RCX: 32006f6c6c6f7061
Apr 01 12:54:34 sanghar kernel: RDX: 0000000000000001 RSI: ffffc900006f3dfc RDI: ffff88009b11b400
Apr 01 12:54:34 sanghar kernel: RBP: ffffc900006f3de8 R08: 0000000000000001 R09: 0000000000000363
Apr 01 12:54:34 sanghar kernel: R10: 00000000000000dc R11: 0000000000000363 R12: ffff880086c5c240
Apr 01 12:54:34 sanghar kernel: R13: 0000000000000040 R14: ffffffffa065f000 R15: 0000000000000246
Apr 01 12:54:34 sanghar kernel: FS:  0000000000000000(0000) GS:ffff88011fd00000(0000) knlGS:0000000000000000
Apr 01 12:54:34 sanghar kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Apr 01 12:54:34 sanghar kernel: CR2: 00007f0934283cc4 CR3: 0000000001a09000 CR4: 00000000000406e0
Apr 01 12:54:34 sanghar kernel: Call Trace:
Apr 01 12:54:34 sanghar kernel:  spk_ttyio_out+0x6d/0xb0 [speakup]
Apr 01 12:54:34 sanghar kernel:  do_catch_up+0x142/0x259 [speakup_apollo]
Apr 01 12:54:34 sanghar kernel:  speakup_thread+0x222/0x230 [speakup]
Apr 01 12:54:34 sanghar kernel:  ? wake_atomic_t_function+0x60/0x60
Apr 01 12:54:34 sanghar kernel:  kthread+0x101/0x140
Apr 01 12:54:34 sanghar kernel:  ? synth_release+0x20/0x20 [speakup]
Apr 01 12:54:34 sanghar kernel:  ? kthread_create_on_node+0x60/0x60
Apr 01 12:54:34 sanghar kernel:  ret_from_fork+0x2c/0x40
Apr 01 12:54:34 sanghar kernel: Code: 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 55 48 89 e5 41 56 41 55 41 54 53 4c 8b b7 68 02 00 00 49 8b 06 48 8b 08 <8b> 49 18 85 c9 74 75 41 89 d4 49 89 f5 48 89 fb 66 66 66 66 90
Apr 01 12:54:34 sanghar kernel: RIP: serial_write+0x1d/0xa0 [usbserial] RSP: ffffc900006f3dc8
Apr 01 12:54:34 sanghar kernel: ---[ end trace 27b76f7f163ce3c9 ]---