Re: [lcd4linux] Problems with Parport and HD44780 driver

[Stefan U. H. <suh...@gm...>]

Hi there,

me again ...

Am 04.04.2015 um 23:10 schrieb Stefan U. Hegner:
> I got no clue about the lowlevel timings. I now just took the example
> from the website and replaced the old fuzz-setting:
>
>      Timing {
>         CY    1000  
>         PW     450  
>         AS     140  
>         AH      20  
>         INIT1 4100
>         INIT2  100
>         EXEC    80
>         WRCG   120
>         CLEAR 2250
>         HOME  2250
>         ONOFF 2250
>         GPO_ST  20
>         GPO_PW 230
>         POWER  500
>      }
>
> For the moment, this seems to work. 
It was wise to be a bit sceptic.

About twelve hours later, lcd4linux hung again. Here's the snippet from
my syslog:

    Apr  5 11:46:56 zomba kernel: INFO: task lcd4linux:14452 blocked for
    more than 120 seconds.
    Apr  5 11:46:56 zomba kernel:       Not tainted 3.16.0-4-amd64 #1
    Apr  5 11:46:56 zomba kernel: "echo 0 >
    /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    Apr  5 11:46:56 zomba kernel: lcd4linux       D ffff8803adfdce78    
    0 14452      1 0x00000000
    Apr  5 11:46:56 zomba kernel:  ffff8803adfdca20 0000000000000082
    0000000000012f00 ffff880439b43fd8
    Apr  5 11:46:56 zomba kernel:  0000000000012f00 ffff8803adfdca20
    ffffffffa02bc040 ffff880439b43e78
    Apr  5 11:46:56 zomba kernel:  ffffffffa02bc044 ffff8803adfdca20
    00000000ffffffff ffffffffa02bc048
    Apr  5 11:46:56 zomba kernel: Call Trace:
    Apr  5 11:46:56 zomba kernel:  [<ffffffff8150cb35>] ?
    schedule_preempt_disabled+0x25/0x70
    Apr  5 11:46:56 zomba kernel:  [<ffffffff8150e5e3>] ?
    __mutex_lock_slowpath+0xd3/0x1c0
    Apr  5 11:46:56 zomba kernel:  [<ffffffff8150e6eb>] ?
    mutex_lock+0x1b/0x2a
    Apr  5 11:46:56 zomba kernel:  [<ffffffffa02b9387>] ?
    pp_ioctl+0x27/0x970 [ppdev]
    Apr  5 11:46:56 zomba kernel:  [<ffffffff811c92d3>] ?
    seq_read+0x1b3/0x360
    Apr  5 11:46:56 zomba kernel:  [<ffffffff811b9ecf>] ?
    do_vfs_ioctl+0x2cf/0x4b0
    Apr  5 11:46:56 zomba kernel:  [<ffffffff812063d5>] ?
    proc_reg_read+0x45/0x70
    Apr  5 11:46:56 zomba kernel:  [<ffffffff811a7ae3>] ?
    vfs_read+0x93/0x170
    Apr  5 11:46:56 zomba kernel:  [<ffffffff811ba131>] ?
    SyS_ioctl+0x81/0xa0
    Apr  5 11:46:56 zomba kernel:  [<ffffffff8150ff6d>] ?
    system_call_fast_compare_end+0x10/0x15
    [...]
    Apr  5 11:48:56 zomba kernel: INFO: task lcd4linux:14452 blocked for
    more than 120 seconds.
    Apr  5 11:48:56 zomba kernel:       Not tainted 3.16.0-4-amd64 #1
    Apr  5 11:48:56 zomba kernel: "echo 0 >
    /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    Apr  5 11:48:56 zomba kernel: lcd4linux       D ffff8803adfdce78    
    0 14452      1 0x00000000
    Apr  5 11:48:56 zomba kernel:  ffff8803adfdca20 0000000000000082
    0000000000012f00 ffff880439b43fd8
    Apr  5 11:48:56 zomba kernel:  0000000000012f00 ffff8803adfdca20
    ffffffffa02bc040 ffff880439b43e78
    Apr  5 11:48:56 zomba kernel:  ffffffffa02bc044 ffff8803adfdca20
    00000000ffffffff ffffffffa02bc048
    Apr  5 11:48:56 zomba kernel: Call Trace:
    Apr  5 11:48:56 zomba kernel:  [<ffffffff8150cb35>] ?
    schedule_preempt_disabled+0x25/0x70
    Apr  5 11:48:56 zomba kernel:  [<ffffffff8150e5e3>] ?
    __mutex_lock_slowpath+0xd3/0x1c0
    Apr  5 11:48:56 zomba kernel:  [<ffffffff8150e6eb>] ?
    mutex_lock+0x1b/0x2a
    Apr  5 11:48:56 zomba kernel:  [<ffffffffa02b9387>] ?
    pp_ioctl+0x27/0x970 [ppdev]
    Apr  5 11:48:56 zomba kernel:  [<ffffffff811c92d3>] ?
    seq_read+0x1b3/0x360
    Apr  5 11:48:56 zomba kernel:  [<ffffffff811b9ecf>] ?
    do_vfs_ioctl+0x2cf/0x4b0
    Apr  5 11:48:56 zomba kernel:  [<ffffffff812063d5>] ?
    proc_reg_read+0x45/0x70
    Apr  5 11:48:56 zomba kernel:  [<ffffffff811a7ae3>] ?
    vfs_read+0x93/0x170
    Apr  5 11:48:56 zomba kernel:  [<ffffffff811ba131>] ?
    SyS_ioctl+0x81/0xa0
    Apr  5 11:48:56 zomba kernel:  [<ffffffff8150ff6d>] ?
    system_call_fast_compare_end+0x10/0x15
    [...]
    Apr  5 11:50:56 zomba kernel: INFO: task lcd4linux:14452 blocked for
    more than 1
    20 seconds.
    Apr  5 11:50:56 zomba kernel:       Not tainted 3.16.0-4-amd64 #1
    Apr  5 11:50:56 zomba kernel: "echo 0 >
    /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    Apr  5 11:50:56 zomba kernel: lcd4linux       D ffff8803adfdce78    
    0 14452      1 0x00000000
    Apr  5 11:50:56 zomba kernel:  ffff8803adfdca20 0000000000000082
    0000000000012f00 ffff880439b43fd8
    Apr  5 11:50:56 zomba kernel:  0000000000012f00 ffff8803adfdca20
    ffffffffa02bc040 ffff880439b43e78
    Apr  5 11:50:56 zomba kernel:  ffffffffa02bc044 ffff8803adfdca20
    00000000ffffffff ffffffffa02bc048
    Apr  5 11:50:56 zomba kernel: Call Trace:
    Apr  5 11:50:56 zomba kernel:  [<ffffffff8150cb35>] ?
    schedule_preempt_disabled+0x25/0x70
    Apr  5 11:50:56 zomba kernel:  [<ffffffff8150e5e3>] ?
    __mutex_lock_slowpath+0xd3/0x1c0
    Apr  5 11:50:56 zomba kernel:  [<ffffffff8150e6eb>] ?
    mutex_lock+0x1b/0x2a
    Apr  5 11:50:56 zomba kernel:  [<ffffffffa02b9387>] ?
    pp_ioctl+0x27/0x970 [ppdev]
    Apr  5 11:50:56 zomba kernel:  [<ffffffff811c92d3>] ?
    seq_read+0x1b3/0x360
    Apr  5 11:50:56 zomba kernel:  [<ffffffff811b9ecf>] ?
    do_vfs_ioctl+0x2cf/0x4b0
    Apr  5 11:50:56 zomba kernel:  [<ffffffff812063d5>] ?
    proc_reg_read+0x45/0x70
    Apr  5 11:50:56 zomba kernel:  [<ffffffff811a7ae3>] ?
    vfs_read+0x93/0x170
    Apr  5 11:50:56 zomba kernel:  [<ffffffff811ba131>] ?
    SyS_ioctl+0x81/0xa0
    Apr  5 11:50:56 zomba kernel:  [<ffffffff8150ff6d>] ?
    system_call_fast_compare_end+0x10/0x15
    [...]

... this keeps on repeating until 12:04:56 every two minutes

Any hints as where to play with are most warmly welcome.

Background to the system:

  * System: Debian 8.0 Jessie
  * Kernel: Linux 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt7-1
    (2015-03-01) x86_64 GNU/Linux
  * lcd4linux Version:  0.11.0~svn1200-3

... happy Easter!

Stefan.

-- 
Stefan U. Hegner 
              <suh...@gm...>
              * * *
D-32584 Löhne --- good ole Germany