Hi,
I recently tried few recent kernels and found out that spi-bcm53xx
fails (rcu_sched) with them. I knew it was working OK with 3.18, so I
tried newer ones one by one and discovered it's a 4.0 regression.
Bisecting pointed following commit:
commit 0461a4149836c792d186027c8c859637a4cfb11a
Author: Mark Brown <broonie@xxxxxxxxxx>
Date: Tue Dec 9 21:38:05 2014 +0000
spi: Pump transfers inside calling context for spi_sync()
I also confirmed that reverting two commits:
spi: Only idle the message pump in the worker kthread
spi: Pump transfers inside calling context for spi_sync()
from top of 4.0.9 (clean), 4.1.16 (clean) and 4.4 (manual) fixes
(workarounds) that issue for me.
Unfortunately the bug in spi-bcm53xx isn't obvious for me. I kept
looking at its code for a bit but couldn't find anything.
Knowing the commit that exposed this bug, does it give you any hint
what may be wrong with spi-bcm53xx?
--
Rafał
[ 74.438399] INFO: rcu_sched self-detected stall on CPU { 0} (t=6000 jiffies g=-116 c=-117 q=12)
[ 74.447203] Task dump for CPU 0:
[ 74.450417] mtd R running 0 505 503 0x00000002
[ 74.456758] Backtrace:
[ 74.459242] [<c001590c>] (dump_backtrace) from [<c0015b1c>] (show_stack+0x18/0x1c)
[ 74.466771] r7:c03e1c40 r6:c03db0fc r5:c7981c00 r4:00000000
[ 74.472447] [<c0015b04>] (show_stack) from [<c003c428>] (sched_show_task+0xb0/0xd0)
[ 74.480069] [<c003c378>] (sched_show_task) from [<c003e210>] (dump_cpu_task+0x34/0x44)
[ 74.487947] r5:00000000 r4:00000000
[ 74.491531] [<c003e1dc>] (dump_cpu_task) from [<c0054354>] (rcu_dump_cpu_stacks+0x7c/0xa0)
[ 74.499750] r5:00000000 r4:c03e1c40
[ 74.503332] [<c00542d8>] (rcu_dump_cpu_stacks) from [<c0056ca8>] (rcu_check_callbacks+0x1d8/0x568)
[ 74.512243] r9:c03da100 r8:c03db148 r7:c7060008 r6:0000000c r5:c6dd4208 r4:c03e1c40
[ 74.520001] [<c0056ad0>] (rcu_check_callbacks) from [<c00589f4>] (update_process_times+0x40/0x60)
[ 74.528823] r10:51eb851f r9:09f12a73 r8:0000001d r7:00000000 r6:00000000 r5:c7981c00
[ 74.536651] r4:c7060000
[ 74.539197] [<c00589b4>] (update_process_times) from [<c006340c>] (tick_periodic+0xa8/0xc0)
[ 74.547503] r7:00000000 r6:c6dd8000 r5:7fffffff r4:c03da140
[ 74.553173] [<c0063364>] (tick_periodic) from [<c0063608>] (tick_handle_periodic+0x30/0x90)
[ 74.561482] r5:7fffffff r4:ffffffff
[ 74.565063] [<c00635d8>] (tick_handle_periodic) from [<c0017dd0>] (twd_handler+0x34/0x40)
[ 74.573198] r9:09f12a73 r8:0000001d r7:c78141c0 r6:c03e5b78 r5:c7805640 r4:00000001
[ 74.580960] [<c0017d9c>] (twd_handler) from [<c00519ec>] (handle_percpu_devid_irq+0x70/0x8c)
[ 74.589355] r5:c7805640 r4:c6dd8000
[ 74.592934] [<c005197c>] (handle_percpu_devid_irq) from [<c004e14c>] (generic_handle_irq+0x28/0x38)
[ 74.601934] r9:09f12a73 r8:00000001 r7:c780e800 r6:c03d6894 r5:00000000 r4:0000001d
[ 74.609686] [<c004e124>] (generic_handle_irq) from [<c004e40c>] (__handle_domain_irq+0x84/0xa8)
[ 74.618341] r5:00000000 r4:00000000
[ 74.621922] [<c004e388>] (__handle_domain_irq) from [<c000866c>] (gic_handle_irq+0x44/0x64)
[ 74.630231] r9:09f12a73 r8:c03e5964 r7:c7061c14 r6:c7061be0 r5:c03db480 r4:c8802100
[ 74.637981] [<c0008628>] (gic_handle_irq) from [<c0009200>] (__irq_svc+0x40/0x54)
[ 74.645431] Exception stack(0xc7061be0 to 0xc7061c28)
[ 74.650465] 1be0: 00000001 c88e0220 6666666c c88e0000 c03da100 c7a4c9b8 ffffa7e2 c03e5964
[ 74.658603] 1c00: c03e5964 09f12a73 51eb851f c7061c34 c7061c38 c7061c28 c01ef8b4 c0209db4
[ 74.666736] 1c20: 60000013 ffffffff
[ 74.670207] r7:c7061c14 r6:ffffffff r5:60000013 r4:c0209db4
[ 74.675886] [<c0209d98>] (bcma_host_soc_read32) from [<c01ef8b4>] (bcm53xxspi_wait.isra.0+0xc0/0x124)
[ 74.685068] [<c01ef7f4>] (bcm53xxspi_wait.isra.0) from [<c01efc18>] (bcm53xxspi_transfer_one+0x300/0x374)
[ 74.694581] r9:09f12a73 r8:c713b52b r7:00000010 r6:00004ad5 r5:00000010 r4:c7a4c9b8
[ 74.702345] [<c01ef918>] (bcm53xxspi_transfer_one) from [<c01ee2c8>] (spi_transfer_one_message+0x70/0x1d0)
[ 74.711948] r10:c7a4c900 r9:00000001 r8:00000000 r7:c7a4c800 r6:00000000 r5:c7061dcc
[ 74.719776] r4:c7061d60 r3:c01ef918
[ 74.723356] [<c01ee258>] (spi_transfer_one_message) from [<c01eea00>] (spi_pump_messages+0x3c8/0x40c)
[ 74.732528] r9:c7061d08 r8:c7061d60 r7:00000000 r6:c7a4c800 r5:c7a4c95c r4:c7a4c94c
[ 74.740281] [<c01ee638>] (spi_pump_messages) from [<c01ef4d4>] (__spi_sync+0x148/0x170)
[ 74.748244] r10:c7a4c900 r9:c7061d08 r8:c7a4c95c r7:00000000 r6:c7a4c800 r5:c7a4c960
[ 74.756073] r4:c7061d60
[ 74.758605] [<c01ef38c>] (__spi_sync) from [<c01ef510>] (spi_sync+0x14/0x18)
[ 74.765620] r10:c7a6ce00 r9:00000000 r8:c7a48810 r7:c7061d60 r6:c7061ef8 r5:01c40000
[ 74.773447] r4:00000005
[ 74.775981] [<c01ef4fc>] (spi_sync) from [<c01dda0c>] (bcm53xxspiflash_read+0xd0/0xfc)
[ 74.783867] [<c01dd93c>] (bcm53xxspiflash_read) from [<c01dc704>] (spi_nor_read+0x60/0x7c)
[ 74.792084] r8:00040000 r7:00000000 r6:01c40000 r5:c7a489f0 r4:00000000
[ 74.798799] [<c01dc6a4>] (spi_nor_read) from [<c01c0c3c>] (part_read+0x50/0x88)
[ 74.806072] r7:c7061f80 r6:00000000 r5:00000000 r4:c7a6ce00
[ 74.811751] [<c01c0bec>] (part_read) from [<c01be308>] (mtd_read+0x6c/0xa4)
[ 74.818677] r9:00000000 r8:c7a6ce00 r6:c7120000 r5:00000000 r4:003b0000
[ 74.825391] [<c01be29c>] (mtd_read) from [<c01c2340>] (mtdchar_read+0x13c/0x204)
[ 74.832753] r10:c7060000 r9:b6ab1010 r8:c7a6ce00 r7:c7061f80 r6:c7120000 r5:003b0000
[ 74.840580] r4:00000000
[ 74.843124] [<c01c2204>] (mtdchar_read) from [<c00a7e84>] (vfs_read+0x9c/0x130)
[ 74.850395] r10:00000000 r9:c7060000 r8:c0008a84 r7:c01c2204 r6:c7061f80 r5:c702f880
[ 74.858223] r4:b4eb1010
[ 74.860757] [<c00a7de8>] (vfs_read) from [<c00a8508>] (SyS_pread64+0x68/0x88)
[ 74.867857] r9:c7060000 r8:c0008a84 r7:01fb0000 r6:c702f880 r5:c702f880 r4:b4eb1010
[ 74.875607] [<c00a84a0>] (SyS_pread64) from [<c00088e0>] (ret_fast_syscall+0x0/0x30)
[ 74.883314] r7:000000b4 r6:00000003 r5:00000000 r4:00000000
