Re: [PATCH v2 2/3] ARM: mm: Fix ifdef around cpu_*_do_[suspend, resume] ops

[Kukjin Kim <kgene.kim@samsung.com>]

On 08/13/14 00:11, Bartlomiej Zolnierkiewicz wrote:
> Ifdef around cpu_\name\()_do_suspend and cpu_\name\()_do_resume
> ops in proc-macros.S should check for CONFIG_ARM_CPU_SUSPEND and
> not CONFIG_PM_SLEEP.  Fix it.
>
> [ Please note that cpu_v7_do_[suspend,resume] code in proc-v7.S
>    already correctly checks for CONFIG_ARM_CPU_SUSPEND, same is
>    true for functions for other architectures. ]
>
> This fix is needed for decoupling suspend/resume and advanced
> cpuidle support on Exynos platform (next patch fixes build for
> config with CONFIG_PM_SLEEP=n and CONFIG_ARM_EXYNOS_CPUIDLE=y).
>
> If this fix is not present then the following OOPS happens on
> the first attempt to go into advanced cpuidle mode (AFTR):
>
> [   22.244143] Unable to handle kernel NULL pointer dereference at virtual address 00000000
> [   22.250759] pgd = c0004000
> [   22.253445] [00000000] *pgd=00000000
> [   22.257012] Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM
> [   22.262906] Modules linked in:
> [   22.265949] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.16.0-next-20140811-dirty #730
> [   22.273757] task: c05dce68 ti: c05d2000 task.ti: c05d2000
> [   22.279139] PC is at 0x0
> [   22.281661] LR is at __cpu_suspend_save+0x4c/0xa8
> [   22.286344] pc : [<00000000>]    lr : [<c00125e0>]    psr: a0000093
> [   22.286344] sp : c05d3ef4  ip : c05da414  fp : 00000001
> [   22.297799] r10: c05da414  r9 : c0609cb0  r8 : 0000000f
> [   22.303008] r7 : c05da444  r6 : 00000038  r5 : ea802c00  r4 : c05d3f14
> [   22.309517] r3 : 00000000  r2 : c05d3f4c  r1 : 00000038  r0 : c05d3f20
> [   22.316029] Flags: NzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
> [   22.323406] Control: 10c5387d  Table: 69d5404a  DAC: 00000015
> [   22.329135] Process swapper/0 (pid: 0, stack limit = 0xc05d2240)
> [   22.335124] Stack: (0xc05d3ef4 to 0xc05d4000)
> [   22.339466] 3ee0:                                              ea802c00 00000038 c05d3f4c
> [   22.347626] 3f00: 00000000 00000007 c00123bc 00000000 c001d468 6a888000 c05d3f4c 80000000
> [   22.355785] 3f20: 00000007 c003d3a0 0000193d eaf9dde4 eaf9dde4 c02ef0c8 c000969c fffffffe
> [   22.363944] 3f40: 00000000 c0037b54 eaf9dbb8 e9d1a380 00000000 c001d468 c0609cb0 00000000
> [   22.372103] 3f60: c0609cb0 c061649e 00000001 c001250c eaf9dbb8 00000001 c0609cb0 c001d618
> [   22.380262] 3f80: c001d5d0 c02ef56c 2d9d2e1e 00000005 eaf9dbb8 c02edcc4 2d9d2e1e 00000005
> [   22.388421] 3fa0: c040446c c05da4ec c040446c eaf9dbb8 c05cfbb0 c004c580 c05dce68 c05b3ae8
> [   22.396580] 3fc0: 00000000 c058bb24 ffffffff ffffffff c058b5e4 00000000 00000000 c05b3ae8
> [   22.404740] 3fe0: c0616994 c05da47c c05b3ae4 c05ddeec 4000406a 40008074 00000000 00000000
> [   22.412909] [<c00125e0>] (__cpu_suspend_save) from [<c00123bc>] (__cpu_suspend+0x5c/0x70)
> [   22.421074] [<c00123bc>] (__cpu_suspend) from [<c05d3f4c>] (init_thread_union+0x1f4c/0x2000)
> [   22.429479] Code: bad PC value
> [   22.432518] ---[ end trace fb90ebf4217d0ad9 ]---
> [   22.437116] Kernel panic - not syncing: Attempted to kill the idle task!
> [   22.443800] Rebooting in 5 seconds..
>
> This patch has been tested on Exynos4210 based Origen board.
>
> Signed-off-by: Bartlomiej Zolnierkiewicz<b.zolnierkie@samsung.com>
> Acked-by: Kyungmin Park<kyungmin.park@samsung.com>
> ---
>   arch/arm/mm/proc-macros.S | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S
> index ee1d805..ba1196c 100644
> --- a/arch/arm/mm/proc-macros.S
> +++ b/arch/arm/mm/proc-macros.S
> @@ -279,7 +279,7 @@ ENTRY(\name\()_processor_functions)
>
>   	.if \suspend
>   	.word	cpu_\name\()_suspend_size
> -#ifdef CONFIG_PM_SLEEP
> +#ifdef CONFIG_ARM_CPU_SUSPEND
>   	.word	cpu_\name\()_do_suspend
>   	.word	cpu_\name\()_do_resume
>   #else

I'm fine on this but need to get ack from Russell.

Russell, how do you think about this?

Note, I already applied this into samsung tree but if you mind, I'll 
revert it.

- Kukjin