Oh sorry for sendig again, I forgot to include the lists 2011/9/27 Maxin John <arm.maxinbjohn at gmail.com>: > > We hit this bug if we are scheduling when we should not be. ie : if we > call schedule() or sleep() from a driver while in an interrupt handler > or holding a spin-lock, that will trigger this bug. This is because of > a bug present in any of the kernel drivers. Do we call schedule() or sleep() explicitly on a kernel driver, or are there 'hidden' calls inside some function? As I had to implement the basic drivers (clock, timer, irq and uart) so far, I didn't call them explicitly. >?Please share the detailed logs. This is the log that I got with printascii bypassing printk: <5>Linux version 2.6.33-arm1 (fernando at fernando-POS-MIG31AG) (gcc version 4.5.2 (Sourcery G++ Lite 2011.03-41) ) #127 Tue Sep 27 09:14:21 BRT 2011 CPU: ARMv7-M Processor [412fc230] revision 0 (ARMv?(11)M) CPU: VIPT nonaliasing data cache, VIPT nonaliasing instruction cache Machine: Stellaris LM3S9B96 <7>On node 0 totalpages: 2048 <7>free_area_init_node: node 0, pgdat 600de1e0, node_mem_map 600f6000 <7> ?DMA zone: 16 pages used for memmap <7> ?DMA zone: 0 pages reserved <7> ?DMA zone: 2032 pages, LIFO batch:0 Built 1 zonelists in Zone order, mobility grouping off. ?Total pages: 2032 <5>Kernel command line: init=/bin/busybox console=ttyS mem=8M <6>PID hash table entries: 32 (order: -5, 128 bytes) <6>Dentry cache hash table entries: 1024 (order: 0, 4096 bytes) <6>Inode-cache hash table entries: 1024 (order: 0, 4096 bytes) <6>Memory: 8MB = 8MB total <5>Memory: 7168k/7168k available, 1024k reserved, 0K highmem <5>Virtual kernel memory layout: ? ?vector ?: 0x00000000 - 0x00001000 ? ( ? 4 kB) ? ?fixmap ?: 0xfff00000 - 0xfffe0000 ? ( 896 kB) ? ?vmalloc : 0x00000000 - 0xffffffff ? (4095 MB) ? ?lowmem ?: 0x60000000 - 0x60800000 ? ( ? 8 MB) ? ?modules : 0x60000000 - 0x60800000 ? ( ? 8 MB) ? ? ?.init : 0x60008000 - 0x6002f000 ? ( 156 kB) ? ? ?.text : 0x6002f000 - 0x600cb000 ? ( 624 kB) ? ? ?.data : 0x600d6000 - 0x600deb40 ? ( ?35 kB) <6>Hierarchical RCU implementation. <6>NR_IRQS:54 <6>console [ttyS0] enabled <6>Calibrating delay loop... <c>3.82 BogoMIPS (lpj=19136) Mount-cache hash table entries: 512 <6>Switching to clocksource timer3 <6>ttyS0 at MMIO 0x4000c000 (irq = 5) is a LM3S9B96 UARTx Port <6>Freeing init memory: 156K <3>BUG: scheduling while atomic: init/1/0xffff0003 [<60032b6d>] (unwind_backtrace+0x1/0x88) from [<600a1379>] (dump_stack+0xd/0x10) [<600a1379>] (dump_stack+0xd/0x10) from [<60034ea5>] (__schedule_bug+0x35/0x40) [<60034ea5>] (__schedule_bug+0x35/0x40) from [<600a17b1>] (schedule+0x2d1/0x2f4) [<600a17b1>] (schedule+0x2d1/0x2f4) from [<6002f791>] (ret_slow_syscall+0x1/0xc) <4>ptrace: can't handle thumb mode <3>BUG: scheduling while atomic: init/1/0x60408008 [<60032b6d>] (unwind_backtrace+0x1/0x88) from [<600a1379>] (dump_stack+0xd/0x10) [<600a1379>] (dump_stack+0xd/0x10) from [<60034ea5>] (__schedule_bug+0x35/0x40) [<60034ea5>] (__schedule_bug+0x35/0x40) from [<600a17b1>] (schedule+0x2d1/0x2f4) [<600a17b1>] (schedule+0x2d1/0x2f4) from [<6002f791>] (ret_slow_syscall+0x1/0xc) Unhandled exception: IPSR = 00000003 LR = fffffff1 CPU: 0 ? ?Not tainted ?(2.6.33-arm1 #127) PC is at account_user_time+0x4/0x60 LR is at account_process_tick+0x4d/0x58 pc : [<60038168>] ? ?lr : [<60038389>] ? ?psr: 01000223 sp : 60418038 ?ip : 000002cc ?fp : 00000000 r10: 01000000 ?r9 : 604d1f36 ?r8 : 00000013 r7 : 6041803c ?r6 : 068e7780 ?r5 : 00000001 ?r4 : ffafdad5 r3 : ffafdad5 ?r2 : 00000001 ?r1 : 00000001 ?r0 : ffafdad5 Att, Fernando Akira Endo
