BUG: sleeping function called from invalid context

[Fabio Estevam]

Peter,

On Wed, Nov 23, 2011 at 9:36 AM, Peter Rusko <rusko.peter at prolan.hu> wrote:
> Hi all,
>
> While trying to use the LRADC and touchscreen functionality on imx28,
> I've run into this problem:
>
> udevd[523]: starting version 171
> BUG: sleeping function called from invalid context at kernel/mutex.c:271
> in_atomic(): 1, irqs_disabled(): 128, pid: 523, name: udevd
> no locks held by udevd/523.
> irq event stamp: 956
> hardirqs last  enabled at (956): [<c032e56c>]
> _raw_write_unlock_irqrestore+0x3c/0x68
> hardirqs last disabled at (955): [<c032e6ec>]
> _raw_write_lock_irqsave+0x1c/0x58
> softirqs last  enabled at (843): [<c0025c78>] irq_exit+0x54/0xb0
> softirqs last disabled at (792): [<c0025c78>] irq_exit+0x54/0xb0
> [<c0013238>] (unwind_backtrace+0x0/0xe0) from [<c032d198>]
> (mutex_lock_nested+0x24/0x31c)
> [<c032d198>] (mutex_lock_nested+0x24/0x31c) from [<c0017570>]
> (clk_enable+0x20/0x48)
> [<c0017570>] (clk_enable+0x20/0x48) from [<c023173c>]
> (pl011_console_write+0x20/0x78)
> [<c023173c>] (pl011_console_write+0x20/0x78) from [<c0020780>]
> (__call_console_drivers+0x84/0x9c)
> [<c0020780>] (__call_console_drivers+0x84/0x9c) from [<c0020ba0>]
> (console_unlock+0xfc/0x1ec)
> [<c0020ba0>] (console_unlock+0xfc/0x1ec) from [<c0021150>]
> (vprintk+0x3b0/0x440)
> [<c0021150>] (vprintk+0x3b0/0x440) from [<c032b4d4>] (printk+0x18/0x24)
> [<c032b4d4>] (printk+0x18/0x24) from [<c0233a5c>] (kmsg_writev+0xd8/0xfc)
> [<c0233a5c>] (kmsg_writev+0xd8/0xfc) from [<c008f58c>]
> (do_sync_write+0x98/0xd4)
> [<c008f58c>] (do_sync_write+0x98/0xd4) from [<c008fe98>]
> (vfs_write+0xc8/0x138)
> [<c008fe98>] (vfs_write+0xc8/0x138) from [<c00900e0>] (sys_write+0x3c/0x68)
> [<c00900e0>] (sys_write+0x3c/0x68) from [<c000e180>]
> (ret_fast_syscall+0x0/0x38)
>
> It seems that the printk calls cause the problem (it's not just with udev,
> seems to have the problem with all printk calls). The touchscreen
> works perfectly and I'd like to submit a patch which supports it, but I
> keep getting the same messages. What can cause the problem, why is it an
> atomic context within the udevd?

Looks like the same error I faced before:
http://marc.info/?l=linux-arm-kernel&m=131914543319956&w=2

Regards,

Fabio Estevam