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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-24 05:04:00 +08:00
linux-next/arch
Mike Turquette 2b25d9f64b ARM: 7535/1: Reprogram smp_twd based on new common clk framework notifiers
Running cpufreq driver on imx6q, the following warning is seen.

$ BUG: sleeping function called from invalid context at kernel/mutex.c:269

<snip>

stack backtrace:
Backtrace:
[<80011d64>] (dump_backtrace+0x0/0x10c) from [<803fc164>] (dump_stack+0x18/0x1c)
 r6:bf8142e0 r5:bf814000 r4:806ac794 r3:bf814000
[<803fc14c>] (dump_stack+0x0/0x1c) from [<803fd444>] (print_usage_bug+0x250/0x2b
8)
[<803fd1f4>] (print_usage_bug+0x0/0x2b8) from [<80060f90>] (mark_lock+0x56c/0x67
0)
[<80060a24>] (mark_lock+0x0/0x670) from [<80061a20>] (__lock_acquire+0x98c/0x19b
4)
[<80061094>] (__lock_acquire+0x0/0x19b4) from [<80062f14>] (lock_acquire+0x68/0x
7c)
[<80062eac>] (lock_acquire+0x0/0x7c) from [<80400f28>] (mutex_lock_nested+0x78/0
x344)
 r7:00000000 r6:bf872000 r5:805cc858 r4:805c2a04
[<80400eb0>] (mutex_lock_nested+0x0/0x344) from [<803089ac>] (clk_get_rate+0x1c/
0x58)
[<80308990>] (clk_get_rate+0x0/0x58) from [<80013c48>] (twd_update_frequency+0x1
8/0x50)
 r5:bf253d04 r4:805cadf4
[<80013c30>] (twd_update_frequency+0x0/0x50) from [<80068e20>] (generic_smp_call
_function_single_interrupt+0xd4/0x13c)
 r4:bf873ee0 r3:80013c30
[<80068d4c>] (generic_smp_call_function_single_interrupt+0x0/0x13c) from [<80013
34c>] (handle_IPI+0xc0/0x194)
 r8:00000001 r7:00000000 r6:80574e48 r5:bf872000 r4:80593958
[<8001328c>] (handle_IPI+0x0/0x194) from [<800084e8>] (gic_handle_irq+0x58/0x60)
 r8:00000000 r7:bf873f8c r6:bf873f58 r5:80593070 r4:f4000100
r3:00000005
[<80008490>] (gic_handle_irq+0x0/0x60) from [<8000e124>] (__irq_svc+0x44/0x60)
Exception stack(0xbf873f58 to 0xbf873fa0)
3f40:                                                       00000001 00000001
3f60: 00000000 bf814000 bf872000 805cab48 80405aa4 80597648 00000000 412fc09a
3f80: bf872000 bf873fac bf873f70 bf873fa0 80063844 8000f1f8 20000013 ffffffff
 r6:ffffffff r5:20000013 r4:8000f1f8 r3:bf814000
[<8000f1b8>] (default_idle+0x0/0x4c) from [<8000f428>] (cpu_idle+0x98/0x114)
[<8000f390>] (cpu_idle+0x0/0x114) from [<803f9834>] (secondary_start_kernel+0x11
c/0x140)
[<803f9718>] (secondary_start_kernel+0x0/0x140) from [<103f9234>] (0x103f9234)
 r6:10c03c7d r5:0000001f r4:4f86806a r3:803f921c

It looks that the warning is caused by that twd_update_frequency() gets
called from an atomic context while it calls clk_get_rate() where a
mutex gets held.

To fix the warning, let's convert common clk users over to clk notifiers
in place of CPUfreq notifiers.  This works out nicely for Cortex-A9
MPcore designs that scale all CPUs at the same frequency.

Platforms that have not been converted to the common clk framework and
support CPUfreq will rely on the old mechanism.  Once these platforms
are converted over fully then we can remove the CPUfreq-specific bits
for good.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-09-19 22:04:43 +01:00
..
alpha alpha: Fix fall-out from disintegrating asm/system.h 2012-08-19 08:41:19 -07:00
arm ARM: 7535/1: Reprogram smp_twd based on new common clk framework notifiers 2012-09-19 22:04:43 +01:00
avr32 ipc: use Kconfig options for __ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION 2012-07-30 17:25:21 -07:00
blackfin Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lliubbo/blackfin 2012-09-12 07:12:53 +08:00
c6x Enable atomic64 ops in C6X 2012-08-17 08:10:12 -07:00
cris ipc: use Kconfig options for __ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION 2012-07-30 17:25:21 -07:00
frv Merge branch 'akpm' (Andrew's patch-bomb) 2012-07-30 17:25:34 -07:00
h8300 ipc: use Kconfig options for __ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION 2012-07-30 17:25:21 -07:00
hexagon Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2012-07-30 11:24:53 -07:00
ia64 [IA64] defconfig: Remove CONFIG_MISC_DEVICES 2012-08-20 13:04:29 -07:00
m32r ipc: use Kconfig options for __ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION 2012-07-30 17:25:21 -07:00
m68k m68k: select CONFIG_GENERIC_ATOMIC64 for all m68k CPU types 2012-08-17 10:04:24 +10:00
microblaze Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k 2012-08-03 10:52:41 -07:00
mips MIPS: pci-ar724x: avoid data bus error due to a missing PCIe module 2012-08-23 15:44:47 +02:00
mn10300 Merge branch 'akpm' (Andrew's patch-bomb) 2012-07-30 17:25:34 -07:00
openrisc Remove useless wrappers of asm-generic/rmap.h 2012-06-28 11:29:26 +02:00
parisc [PARISC] fix personality flag check in copy_thread() 2012-08-03 11:25:12 +01:00
powerpc powerpc: Don't use __put_user() in patch_instruction 2012-09-05 16:05:23 +10:00
s390 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-09-14 17:43:45 -07:00
score new helper: signal_delivered() 2012-06-01 12:58:52 -04:00
sh Merge branches 'sh/urgent' and 'sh/gpiolib' into sh-latest 2012-08-09 13:21:13 +09:00
sparc sparc64: Be less verbose during vmemmap population. 2012-08-15 00:37:29 -07:00
tile memcg: rename config variables 2012-07-31 18:42:43 -07:00
um uml: fix compile error in deliver_alarm() 2012-09-05 19:40:59 -07:00
unicore32 PCI changes for the 3.6 merge window: 2012-07-24 16:17:07 -07:00
x86 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-09-14 17:43:45 -07:00
xtensa xtensa: select generic atomic64_t support 2012-07-31 18:42:39 -07:00
.gitignore
Kconfig ipc: use Kconfig options for __ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION 2012-07-30 17:25:21 -07:00