From mboxrd@z Thu Jan 1 00:00:00 1970 From: rusko.peter@prolan.hu (Peter Rusko) Date: Wed, 23 Nov 2011 12:36:02 +0100 Subject: BUG: sleeping function called from invalid context Message-ID: <4ECCDAA2.4070502@prolan.hu> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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): [] _raw_write_unlock_irqrestore+0x3c/0x68 hardirqs last disabled at (955): [] _raw_write_lock_irqsave+0x1c/0x58 softirqs last enabled at (843): [] irq_exit+0x54/0xb0 softirqs last disabled at (792): [] irq_exit+0x54/0xb0 [] (unwind_backtrace+0x0/0xe0) from [] (mutex_lock_nested+0x24/0x31c) [] (mutex_lock_nested+0x24/0x31c) from [] (clk_enable+0x20/0x48) [] (clk_enable+0x20/0x48) from [] (pl011_console_write+0x20/0x78) [] (pl011_console_write+0x20/0x78) from [] (__call_console_drivers+0x84/0x9c) [] (__call_console_drivers+0x84/0x9c) from [] (console_unlock+0xfc/0x1ec) [] (console_unlock+0xfc/0x1ec) from [] (vprintk+0x3b0/0x440) [] (vprintk+0x3b0/0x440) from [] (printk+0x18/0x24) [] (printk+0x18/0x24) from [] (kmsg_writev+0xd8/0xfc) [] (kmsg_writev+0xd8/0xfc) from [] (do_sync_write+0x98/0xd4) [] (do_sync_write+0x98/0xd4) from [] (vfs_write+0xc8/0x138) [] (vfs_write+0xc8/0x138) from [] (sys_write+0x3c/0x68) [] (sys_write+0x3c/0x68) from [] (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? Regards, -- Rusk? P?ter Fejleszt?m?rn?k Prolan Zrt. / Prolan Co. Hungary 2011 Budakal?sz, Szentendrei ?t 1-3. Tel./Phone: +36 20 954 3118 Fax: +36 26 540 420 E-mail: rusko.peter at prolan.hu Web: www.prolan.hu Timezone:CET