On 08/19/2013 06:43 AM, Viresh Kumar wrote:
On 16 August 2013 23:14, Viresh Kumar viresh.kumar@linaro.org wrote:
On 16 August 2013 17:57, Greg KH gregkh@linuxfoundation.org wrote:
Lots of tty and serial changes have happened since -rc5 in linux-next, can you please rebase, and test, these against that tree and resend them if they are still needed?
I have rebased them over latest linux-next and they applied cleanly.. Haven't tested it though.. Will try that next week.
I initially thought that the problem only occurs with a merge to RT kernel otherwise this would have happened to lots of people..
But when I tried latest linux-next/master (as of today), without RT patch I was able to reproduce the issue on Samsung's Arndale board.
[ 129.179314] [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [ 129.187676] [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [ 129.195619] [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) [ 129.204247] [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) from [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0) [ 129.214241] [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0x38) from [<c020a1a8>] (s3c24xx_serial_rx_chars+0) [ 129.224832] [<c020a1a8>] (s3c24xx_serial_rx_chars+0x12c/0x260) from [<c020aae8>] (s3c64xx_serial_handle_irq+) [ 129.235336] [<c020aae8>] (s3c64xx_serial_handle_irq+0x48/0x60) from [<c006aaa0>] (handle_irq_event_percpu+0x) [ 129.245753] [<c006aaa0>] (handle_irq_event_percpu+0x50/0x194) from [<c006ac20>] (handle_irq_event+0x3c/0x5c) [ 129.255407] [<c006ac20>] (handle_irq_event+0x3c/0x5c) from [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) [ 129.264636] [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) from [<c006a4a4>] (generic_handle_irq+0x20/0x30) [ 129.274030] [<c006a4a4>] (generic_handle_irq+0x20/0x30) from [<c000f454>] (handle_IRQ+0x38/0x94) [ 129.282655] [<c000f454>] (handle_IRQ+0x38/0x94) from [<c0008538>] (gic_handle_irq+0x34/0x68) [ 129.290938] [<c0008538>] (gic_handle_irq+0x34/0x68) from [<c00123c0>] (__irq_svc+0x40/0x70) [ 129.299134] Exception stack(0xc04cdf70 to 0xc04cdfb8) [ 129.304084] df60: 00000000 00000000 0000166e 00000000 [ 129.312117] df80: c04cc000 c050278f c050278f 00000001 c04d444c 410fc0f4 c03649b0 00000000 [ 129.320146] dfa0: 00000001 c04cdfb8 c000f758 c000f75c 60070013 ffffffff [ 129.326639] [<c00123c0>] (__irq_svc+0x40/0x70) from [<c000f75c>] (arch_cpu_idle+0x28/0x30) [ 129.334756] [<c000f75c>] (arch_cpu_idle+0x28/0x30) from [<c0054888>] (cpu_startup_entry+0x5c/0x148) [ 129.343644] [<c0054888>] (cpu_startup_entry+0x5c/0x148) from [<c0497aa4>] (start_kernel+0x334/0x38c) [ 133.343767] BUG: spinlock lockup suspected on CPU#0, kworker/0:1/360 [ 133.348574] lock: s3c24xx_serial_ports+0x1d8/0x370, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1 [ 133.357885] CPU: 0 PID: 360 Comm: kworker/0:1 Not tainted 3.11.0-rc6-next-20130819-00003-g75485f1 #2 [ 133.366858] Workqueue: events flush_to_ldisc [ 133.371034] [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [ 133.379413] [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [ 133.387355] [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) [ 133.395982] [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) from [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) [ 133.405635] [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) from [<c0203224>] (uart_start+0x18/0x34) [ 133.414602] [<c0203224>] (uart_start+0x18/0x34) from [<c01ef890>] (__receive_buf+0x4b4/0x738) [ 133.422973] [<c01ef890>] (__receive_buf+0x4b4/0x738) from [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) [ 133.432026] [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) from [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) [ 133.441081] [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) from [<c0031af0>] (process_one_work+0xfc/0x348) [ 133.450048] [<c0031af0>] (process_one_work+0xfc/0x348) from [<c0032138>] (worker_thread+0x138/0x37c) [ 133.459014] [<c0032138>] (worker_thread+0x138/0x37c) from [<c0037a7c>] (kthread+0xa4/0xb0) [ 133.467128] [<c0037a7c>] (kthread+0xa4/0xb0) from [<c000e5f8>] (ret_from_fork+0x14/0x3c)
And so yes they are required over latest linux-next as well.. I will resend V2 soon. Thanks..
Umm. How did a worker thread schedule while an IRQ handler was holding a irq-disabling spin lock?
Regards, Peter Hurley
PS - please paste your stack backtraces with line-wrap disabled