On 04/19/11 16:22, Hennerich, Michael wrote:
> Hi Jonathan,
>
> The AD7606 ring buffer doesn't use the thread, and installs only the hard handler.
>
> indio_dev->pollfunc->h = &ad7606_trigger_handler_th;
> indio_dev->pollfunc->thread = NULL;
>
> This crashes the system in handle_nested_irq (null pointer action->thread_fn)
> called from iio_trigger_poll_chained().
I knew that wouldn't work, but didn't realize it wouldn't just fail with
an error...
The only thing I can think to do is to actually set both h and thread
to ad7606_trigger_handler_th.
As it returns IRQ_HANDLED, if it is called via irq_trigger_poll, it will
happen in interrupt context and thread will never run.
If it is called via irq_trigger_poll_handler (e.g. for non interrupt context)
it'll happen outside interrupt context. Given timing is never going to
be that tight for userspace triggers, this probably isn't a problem.
Can you try that out and see if it works?
>
> root:/> echo 1 > /sys/bus/iio/devices/trigger0/trigger_now
> Jump to NULL address
> Kernel OOPS in progress
> Deferred Exception context
> CURRENT PROCESS:
> COMM=sh PID=166 CPU=0
> TEXT = 0x02a00040-0x02a54380 DATA = 0x02a543a0-0x02a68d28
> BSS = 0x02a68d28-0x02a6a6e0 USER-STACK = 0x02a73fa4
>
> return address: [0x (null)]; contents of:
>
> ADSP-BF537-0.2 500(MHz CCLK) 125(MHz SCLK) (mpu off)
> Linux version 2.6.39-rc3-00802-g1f36cb3-dirty (michael@mhenneri-D02) (gcc version 4.3.5 (ADI-trunk/svn-5074) ) #84 Tue Apr 19 17:09:10 CEST 2011
>
> SEQUENCER STATUS: Not tainted
> SEQSTAT: 0000002d IPEND: 8008 IMASK: ffff SYSCFG: 0006
> EXCAUSE : 0x2d
> physical IVG3 asserted : <0xffa007b4> { _trap + 0x0 }
> physical IVG15 asserted : <0xffa01098> { _evt_system_call + 0x0 }
> logical irq 6 mapped : <0xffa003c8> { _bfin_coretmr_interrupt + 0x0 }
> logical irq 10 mapped : <0x000c0278> { _bfin_rtc_interrupt + 0x0 }
> logical irq 16 mapped : <0x000c2114> { _bfin_twi_interrupt_entry + 0x0 }
> logical irq 18 mapped : <0x000ab53c> { _bfin_serial_dma_rx_int + 0x0 }
> logical irq 19 mapped : <0x000ab29c> { _bfin_serial_dma_tx_int + 0x0 }
> logical irq 24 mapped : <0x000baa40> { _bfin_mac_interrupt + 0x0 }
> logical irq 54 mapped : <0x000cce0c> { _ad7606_interrupt + 0x0 }
> logical irq 106 mapped : <0x000cd390> { _ad7606_trigger_handler_th + 0x0 }
> RETE: <0x00000000> /* Maybe null pointer? */
> RETN: <0x028f7e3c> /* kernel dynamic memory (maybe user-space) */
> RETX: <0x00000480> /* Maybe fixed code section */
> RETS: <0x00036778> { _handle_nested_irq + 0x58 }
> PC : <0x00000000> /* Maybe null pointer? */
> DCPLB_FAULT_ADDR: <0x028e71f4> /* kernel dynamic memory (maybe user-space) */
> ICPLB_FAULT_ADDR: <0x00000000> /* Maybe null pointer? */
> PROCESSOR STATE:
> R0 : 0000006a R1 : 027f8c80 R2 : 00000000 R3 : 028dc3c4
> R4 : 026cf860 R5 : 028e77b4 R6 : 00000002 R7 : 0000006a
> P0 : 02078002 P1 : 00000089 P2 : 00000000 P3 : 00130080
> P4 : 00195efc P5 : 0019b488 FP : 028f7ef0 SP : 028f7d60
> LB0: ffa01778 LT0: ffa01776 LC0: 00000000
> LB1: 02a0cfdd LT1: 02a0cf92 LC1: 00000000
> B0 : 00000001 L0 : 00000000 M0 : 0000002c I0 : 00195efc
> B1 : 00000001 L1 : 00000000 M1 : 00000001 I1 : 02a73d88
> B2 : 02a739c3 L2 : 00000000 M2 : 00000000 I2 : 02a68a20
> B3 : 00000001 L3 : 00000000 M3 : 00000000 I3 : 00000000
> A0.w: 00000000 A0.x: 00000000 A1.w: 00000000 A1.x: 00000000
> USP : 02a73d10 ASTAT: 02000020
>
> Hardware Trace:
> 0 Target : <0x00003fa8> { _trap_c + 0x0 }
> Source : <0xffa00748> { _exception_to_level5 + 0xa4 } JUMP.L
> 1 Target : <0xffa006a4> { _exception_to_level5 + 0x0 }
> Source : <0xffa00558> { _bfin_return_from_exception + 0x20 } RTX
> 2 Target : <0xffa00538> { _bfin_return_from_exception + 0x0 }
> Source : <0xffa005fc> { _ex_trap_c + 0x74 } JUMP.S
> 3 Target : <0xffa00588> { _ex_trap_c + 0x0 }
> Source : <0xffa0081c> { _trap + 0x68 } JUMP (P4)
> 4 Target : <0xffa007d2> { _trap + 0x1e }
> Source : <0xffa007ce> { _trap + 0x1a } IF CC JUMP pcrel
> 5 Target : <0xffa007b4> { _trap + 0x0 }
> FAULT : <0x00000000> /* Maybe null pointer? */
> Source : <0x00036776> { _handle_nested_irq + 0x56 } CALL (P2)
> 6 Target : <0x00036732> { _handle_nested_irq + 0x12 }
> Source : <0xffa0214c> { __cond_resched + 0x20 } RTS
> 7 Target : <0xffa02146> { __cond_resched + 0x1a }
> Source : <0xffa0213e> { __cond_resched + 0x12 } IF CC JUMP pcrel (BP)
> 8 Target : <0xffa0212c> { __cond_resched + 0x0 }
> Source : <0x0003672e> { _handle_nested_irq + 0xe } JUMP.L
> 9 Target : <0x0003672c> { _handle_nested_irq + 0xc }
> Source : <0x000348e6> { _irq_to_desc + 0x1a } RTS
> 10 Target : <0x000348cc> { _irq_to_desc + 0x0 }
> Source : <0x00036728> { _handle_nested_irq + 0x8 } JUMP.L
> 11 Target : <0x00036720> { _handle_nested_irq + 0x0 }
> Source : <0x000cbd2c> { _iio_trigger_poll_chained + 0x58 } JUMP.L
> 12 Target : <0x000cbd22> { _iio_trigger_poll_chained + 0x4e }
> Source : <0x000cbcf0> { _iio_trigger_poll_chained + 0x1c } IF !CC JUMP pcrel
> 13 Target : <0x000cbcd4> { _iio_trigger_poll_chained + 0x0 }
> Source : <0x000cd518> { _iio_sysfs_trigger_poll + 0xc } CALL pcrel
> 14 Target : <0x000cd514> { _iio_sysfs_trigger_poll + 0x8 }
> Source : <0x000afdf2> { _dev_get_drvdata + 0x16 } RTS
> 15 Target : <0x000afde6> { _dev_get_drvdata + 0xa }
> Source : <0x000afde0> { _dev_get_drvdata + 0x4 } IF !CC JUMP pcrel
> Kernel Stack
> Stack info:
> SP: [0x028f7f24] <0x028f7f24> /* kernel dynamic memory (maybe user-space) */
> Memory from 0x028f7f20 to 028f8000
> 028f7f20: 7fffffff [02a039de]
> 00000000 00000000 028f8000 02a039de 02a039de
> 028f7f40: 02a158ea ffa010fc 02001004 02a0cfdd 02a0cdcd 02a0cf92 02a0cdca 00000000
> 028f7f60: 00000000 00000000 00000000 00000000 00000000 00000001 02a739c3 00000001
> 028f7f80: 00000001 00000000 00000000 00000000 00000000 00000000 00000000 00000001
> 028f7fa0: 00000000 00000000 02a68a20 02a73d88 029ea578 02a73d10 02a73d1c 02a695c8
> 028f7fc0: 02a6870c 02a73d94 02a695ca 02a6870c 00000004 00000002 00000002 7fffffff
> 028f7fe0: 00000000 00000000 00000002 02a695c8 00000001 00000001 00000004 00000006
> Return addresses in stack:
> address : <0x00008000> { _show_regs + 0x154 }
> Modules linked in:
> Kernel panic - not syncing: Kernel exception
> Hardware Trace:
> Stack info:
> SP: [0x028f7c68] <0x028f7c68> /* kernel dynamic memory (maybe user-space) */
> FP: (0x028f7d78)
> Memory from 0x028f7c60 to 028f8000
> 028f7c60: 028f7c68 00000013 [00155970] 00124660 028f7d60 00155970 001893cb 001893cb
> 028f7c80: 001893cb 028f7cb0 028f7ef0 00004464 028f7d60 ffe02014 00130080 00008008
> 028f7ca0: 0000000b 0000002d 00000013 028f7d60 0000003f ffffffff 0007e710 00000000
> 028f7cc0: 0003000b 0005bd68 0000a068 028dc3c4 028f7ec4 01a02a64 00000001 00000000
> 028f7ce0: 00000000 00000000 028f7ec4 0005bc60 02a9d8cc 02a96b54 02a9d8cc 00000002
> 028f7d00: 0000a068 00000000 00000008 00051b04 00000002 02a9d8cc 00000002 00000000
> 028f7d20: 00000000 0004aace 02a96b54 028f7e34 0000002c 00000000 001a38e4 ffa0074c
> 028f7d40: 00186000 00008008 0000002d 028e77b4 026cf860 009c5234 00000001 00000480
> 028f7d60: 00000480 00008008 0000002d 00000000 028f7e3c 00000480 (00000000)
> 028f7d80: 0000006a 02000020 02a0cfdd ffa01778 02a0cf92 ffa01776 00000000 00000000
> 028f7da0: 00000000 00000000 00000000 00000000 00000001 02a739c3 00000001 00000001
> 028f7dc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000001 0000002c
> 028f7de0: 00000000 02a68a20 02a73d88 00195efc 02a73d10 028f7ef0 0019b488 00195efc
> 028f7e00: 00130080 00000000 00000089 02078002 0000006a 00000002 028e77b4 026cf860
> 028f7e20: 028dc3c4 00000000 027f8c80 0000006a 0000006a 02078002 00000006 a92f6ddb
> 028f7e40: 001a38c0 028f7ef0 000cbd30 029a0200 028dc3c4 029a0210 00000000 00000002
> 028f7e60: 028e77b4 000cd51c 028e77a0 00000000 0007eabc 029a0210 <0007eb30> 00000000
> 028f7e80: 00000000 00000000 00000002 02a73d1c <0004baa6> 026cf860 00000004 02a73d94
> 028f7ea0: 028f7ef0 00000002 02a695c8 00000000 00000004 00000000 02a73d7c 028f7ef0
> 028f7ec0: 026cf860 00000006 0004bbbc 026cf860 00000004 02a695c8 00000002 7fffffff
> 028f7ee0: 026cf860 00000001 00000000 028f7ef0 00000000 00000000 00000000 <ffa00956>
> 028f7f00: 0004bb8c 00000000 ffffe000 ffffe000 7fffffff 0000fffe 00000000 00000000
> 028f7f20: 7fffffff 02a039de
> 00000000 00000000 028f8000 02a039de 02a039de
> 028f7f40: 02a158ea ffa010fc 02001004 02a0cfdd 02a0cdcd 02a0cf92 02a0cdca 00000000
> 028f7f60: 00000000 00000000 00000000 00000000 00000000 00000001 02a739c3 00000001
> 028f7f80: 00000001 00000000 00000000 00000000 00000000 00000000 00000000 00000001
> 028f7fa0: 00000000 00000000 02a68a20 02a73d88 029ea578 02a73d10 02a73d1c 02a695c8
> 028f7fc0: 02a6870c 02a73d94 02a695ca 02a6870c 00000004 00000002 00000002 7fffffff
> 028f7fe0: 00000000 00000000 00000002 02a695c8 00000001 00000001 00000004 00000006
> Return addresses in stack:
> frame 1 : <0x00036778> { _handle_nested_irq + 0x58 }
> address : <0x0007eb30> { _sysfs_write_file + 0xac }
> address : <0x0004baa6> { _vfs_write + 0x6a }
> address : <0xffa00956> { _system_call + 0x6a }
> address : <0x00008000> { _show_regs + 0x154 }
>
>
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