Hi, I just tried to get the driver working with my lcd display (hd44780 compatible) and the kernel oops'ed - but unfortunately I can't figure out why. Steps to reproduce: 1) compile panel driver with CONFIG_PANEL=m CONFIG_PANEL_PARPORT=0 CONFIG_PANEL_PROFILE=0 CONFIG_PANEL_KEYPAD=0 CONFIG_PANEL_LCD=1 CONFIG_PANEL_LCD_HEIGHT=2 CONFIG_PANEL_LCD_WIDTH=20 CONFIG_PANEL_LCD_BWIDTH=40 CONFIG_PANEL_LCD_HWIDTH=64 CONFIG_PANEL_LCD_CHARSET=1 CONFIG_PANEL_LCD_PROTO=0 CONFIG_PANEL_LCD_PIN_E=6 CONFIG_PANEL_LCD_PIN_RS=4 CONFIG_PANEL_LCD_PIN_RW=5 CONFIG_PANEL_LCD_PIN_BL=0 CONFIG_PANEL_CHANGE_MESSAGE=y CONFIG_PANEL_BOOT_MESSAGE="TEST" 2) modprobe ppdev; modprobe parport_pc; insmod panel.ko #nothing is displayed on lcd :/ 3) echo "abc" > /dev/lcd 4) rmmod panel.ko 5) wait approximately 20sec -> kernel oops I managed to get a (atleast partial) trace of the oops using netconsole: parport0: PC-style at 0x378, irq 7 [PCSPP(,...)] Panel driver version 0.9.5 registered on parport0 (io=0x378). parport0: panel tried to release parport when not owner BUG: unable to handle kernel NULL pointer dereference at 0000000000000040 IP: [<ffffffff8110213b>] __journal_clean_checkpoint_list+0x31/0x89 PGD 13ba35067 PUD 13bf67067 PMD 0 Oops: 0000 [#1] SMP last sysfs file: /sys/devices/platform/w83627ehf.656/in8_input CPU 1 Modules linked in: parport_pc ppdev netconsole parport w83627ehf vboxnetflt vboxnetadp vboxdrv fglrx(P) i2c_piix4 [last unloaded: panel] Pid: 1992, comm: kjournald Tainted: P 2.6.34 #1 939A785GMH/128M/To Be Filled By O.E.M. RIP: 0010:[<ffffffff8110213b>] [<ffffffff8110213b>] __journal_clean_checkpoint_list+0x31/0x89 RSP: 0000:ffff88010af47d20 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88013fe00cf0 RSI: ffff88010af47d34 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff88010af46000 R09: ffff88013fc8a6a0 R10: 00007fffeda29c30 R11: 0000000000000001 R12: ffff88010af47fd8 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88010af47d34 FS: 00007f888881a700(0000) GS:ffff880001900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000040 CR3: 0000000135cb5000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process kjournald (pid: 1992, threadinfo ffff88010af46000, task ffff88013fe00cf0) Stack: 0000000000000000 0000000000000000 0000000000000400 ffff880105afc3e8 [<ffffffff81104036>] ? kjournald+0xde/0x222 [<ffffffff8104673c>] ? autoremove_wake_function+0x0/0x2e [<ffffffff81103f58>] ? kjournald+0x0/0x222 [<ffffffff81046379>] ? kthread+0x79/0x81 [<ffffffff81002c14>] ? kernel_thread_helper+0x4/0x10 [<ffffffff81046300>] ? kthread+0x0/0x81 [<ffffffff81002c10>] ? kernel_thread_helper+0x0/0x10 Code: 31 ec 60 5f 80 8d 89 24 00 4c 6b fe 41 [<ffffffff8110213b>] __journal_clean_checkpoint_list+0x31/0x89 RSP <ffff88010af47d20> CR2: 0000000000000040 ---[ end trace e7cd6b60c2caaf05 ]--- vboxnetadp vboxdrv fglrx(P) i2c_piix4 [last unloaded: panel] Pid: 5559, comm: firefox Tainted: P D 2.6.34 #1 939A785GMH/128M/To Be Filled By O.E.M. RIP: 0010:[<ffffffff813b3feb>] [<ffffffff813b3feb>] _raw_spin_lock+0xa/0x15 RSP: 0018:ffff8801155bfc60 EFLAGS: 00000297 RAX: 0000000000003837 RBX: ffff88013e29c400 RCX: 0000000000002000 RDX: ffff88011571c050 RSI: ffff880129d0c3d8 RDI: ffff88013e29c424 RBP: ffffffff810027ce R08: fffffffffffffff4 R09: 0000000000000000 R10: ffff8801155bfe48 R11: 0000000000000000 R12: 000000000000000b R13: ffff880132466a78 R14: 0000000000000001 R15: 0000000000000000 FS: 00007fa56ee49720(0000) GS:ffff880001800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1a7d4f0000 CR3: 000000011c0c1000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process firefox (pid: 5559, threadinfo ffff8801155be000, task ffff88011571c050) Stack: ffffffff81100435 ffff8801155bfcb0 Seems like the driver registers something that gets called periodically, but forgets to unregister this? Would be great if anyone can help me fixing this issue. Thanks, Peter -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
