Since commit 8b283c0 "ARM: exynos4/5: convert pmu wakeup to stacked domains", a suspend/resume is not supported on old DT. Although, rather than printing a warning and continue to boot, the kernel will segfault just after: ------------[ cut here ]------------ WARNING: CPU: 1 PID: 1 at arch/arm/mach-exynos/suspend.c:726 exynos_pm_init+0x4c/0xc8() Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.1.0-rc3 #1 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [<c02181c4>] (unwind_backtrace) from [<c0213b2c>] (show_stack+0x10/0x14) [<c0213b2c>] (show_stack) from [<c0949890>] (dump_stack+0x70/0x8c) [<c0949890>] (dump_stack) from [<c024f0b0>] (warn_slowpath_common+0x74/0xac) [<c024f0b0>] (warn_slowpath_common) from [<c024f104>] (warn_slowpath_null+0x1c/0x24) [<c024f104>] (warn_slowpath_null) from [<c0cf1d28>] (exynos_pm_init+0x4c/0xc8) [<c0cf1d28>] (exynos_pm_init) from [<c0ceaae8>] (init_machine_late+0x1c/0x28) [<c0ceaae8>] (init_machine_late) from [<c020aa64>] (do_one_initcall+0x80/0x1d0) [<c020aa64>] (do_one_initcall) from [<c0ce8d4c>] (kernel_init_freeable+0x10c/0x1d8) [<c0ce8d4c>] (kernel_init_freeable) from [<c0944a2c>] (kernel_init+0x8/0xe4) [<c0944a2c>] (kernel_init) from [<c0210e60>] (ret_from_fork+0x14/0x34) ---[ end trace 335bd937d409f3c7 ]--- Outdated DT detected, suspend/resume will NOT work Unable to handle kernel NULL pointer dereference at virtual address 00000608 pgd = c0204000 [00000608] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 4.1.0-rc3 #1 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) task: db06c000 ti: db05a000 task.ti: db05a000 PC is at exynos_pm_init+0x6c/0xc8 LR is at exynos_pm_init+0x54/0xc8 pc : [<c0cf1d48>] lr : [<c0cf1d30>] psr: 60000113 sp : db05bee8 ip : 00000000 fp : 00000000 r10: 00000116 r9 : c0dab2d4 r8 : d8d5f440 r7 : c0db7ad8 r6 : c0db7ad8 r5 : 00000000 r4 : c0ceaacc r3 : c0eb2aec r2 : c0951e40 r1 : 00000000 r0 : c0eb2acc Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 6020406a DAC: 00000015 Process swapper/0 (pid: 1, stack limit = 0xdb05a220) Stack: (0xdb05bee8 to 0xdb05c000) bee0: c0db7ad8 c0d8fe34 c0cf17c8 c0ceaae8 00000000 c020aa64 bf00: 00000033 c09580b8 db04fd00 c0ed79a4 c0eb1000 c0ce8588 c0ca2bc4 c0353fcc bf20: 00000000 c0df358c 60000113 00000000 dbfffba4 00000000 c0ca2bc4 c026654c bf40: c0b80134 c0ca1a64 00000007 00000007 c0df3554 c0d6c2f4 00000007 c0d6c2d4 bf60: c0eb1000 c0ce8588 c0dab2d4 00000116 00000000 c0ce8d4c 00000007 00000007 bf80: c0ce8588 c0944a24 00000000 c0944a24 00000000 00000000 00000000 00000000 bfa0: 00000000 c0944a2c 00000000 c0210e60 00000000 00000000 00000000 00000000 bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 [<c0cf1d48>] (exynos_pm_init) from [<c0ceaae8>] (init_machine_late+0x1c/0x28) [<c0ceaae8>] (init_machine_late) from [<c020aa64>] (do_one_initcall+0x80/0x1d0) [<c020aa64>] (do_one_initcall) from [<c0ce8d4c>] (kernel_init_freeable+0x10c/0x1d8) [<c0ce8d4c>] (kernel_init_freeable) from [<c0944a2c>] (kernel_init+0x8/0xe4) [<c0944a2c>] (kernel_init) from [<c0210e60>] (ret_from_fork+0x14/0x34) Code: e59f005c e59220c0 e5901000 e5832000 (e591e608) ---[ end trace 335bd937d409f3c8 ]--- This is happening because pmu_base_addr is only initialized when the PMU is an interrupt controller. It's not the case on old DT. Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx> --- arch/arm/mach-exynos/suspend.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-exynos/suspend.c b/arch/arm/mach-exynos/suspend.c index 3e6aea7..b6f3ddc 100644 --- a/arch/arm/mach-exynos/suspend.c +++ b/arch/arm/mach-exynos/suspend.c @@ -723,8 +723,10 @@ void __init exynos_pm_init(void) return; } - if (WARN_ON(!of_find_property(np, "interrupt-controller", NULL))) + if (WARN_ON(!of_find_property(np, "interrupt-controller", NULL))) { pr_warn("Outdated DT detected, suspend/resume will NOT work\n"); + return; + } pm_data = (const struct exynos_pm_data *) match->data; -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html