记一次DDR翻转导致系统重启

客户反馈有机器开机后重启。

拿到机器后，刷成debug版本的软件，串口打印如下信息

[    0.000000] c0     0 Booting Linux on physical CPU 0x0
[    0.000000] c0     0 Initializing cgroup subsys cpuset
[    0.000000] c0     0 Initializing cgroup subsys cpu
[    0.000000] c0     0 Initializing cgroup subsys cpuacct
[    0.000000] c0     0 Initializing cgroup subsys schedtune
[    0.000000] c0     0 Linux version 4.4.147 (linux@ubuntu01) (gcc version 4.9.x 20150123 (prerelease) (GCC) ) #1 SMP PREEMPT Fri Apr 24 16:03:19 CST 2020
[    0.000000] c0     0 Boot CPU: AArch64 Processor [411fd050]
[    0.000000] c0     0 earlycon: Early serial console at MMIO 0x70100000 (options '115200n8')
[    0.000000] c0     0 bootconsole [uart0] enabled
[    0.000000] c0     0 On node 0 totalpages: 524224
[    0.000000] c0     0   DMA zone: 8191 pages used for memmap
[    0.000000] c0     0   DMA zone: 0 pages reserved
[    0.000000] c0     0   DMA zone: 524224 pages, LIFO batch:31
[    0.000000] c0     0 psci: probing for conduit method from DT.
[    0.000000] c0     0 psci: PSCIv1.0 detected in firmware.
[    0.000000] c0     0 psci: Using standard PSCI v0.2 function IDs
[    0.000000] c0     0 psci: MIGRATE_INFO_TYPE not supported.
[    0.000000] c0     0 PERCPU: Embedded 21 pages/cpu @ffffffc07fe58000 s47512 r8192 d30312 u86016
[    0.000000] pcpu-alloc: s47512 r8192 d30312 u86016 alloc=21*4096
[    0.000000] pcpu-alloc: [0] 0 [0] 1 [0] 2 [0] 3 [0] 4 [0] 5 [0] 6 [0] 7 
[    0.000000] c0     0 Detected VIPT I-cache on CPU0
[    0.000000] c0     0 Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 516033
[    0.000000] c0     0 Kernel command line: earlycon=sprd_serial,0x70100000,115200n8 console=ttyS1,115200n8 loglevel=9 init=/init root=/dev/mmcblk0p30 rootfstype=ext4 ro rootwait androidboot.hardware=s98
[    0.000000] c0     0 androidboot.hardware=s9863a1h10 0
[    0.000000] c0     0 androidboot.hardware=s9863a1h10 1
[    0.000000] c0     0 [sprd-adf][          lcd_id_get] LCD ID from uboot: 0x67191
[    0.000000] c0     0 [sprd-adf][       logo_base_get] logo base from uboot: 0x9d654000
[    0.000000] c0     0 [sprd-adf][       pixel_clk_get] pixel clock from uboot: 67000000
[    0.000000] c0     0 sysdump: [sysdump_magic_setup]SYSDUMP paddr from uboot: 0x85500000
[    0.000000] c0     0 rfboard.id=0 0
[    0.000000] c0     0 PID hash table entries: 4096 (order: 3, 32768 bytes)
[    0.000000] c0     0 Dentry cache hash table entries: 262144 (order: 9, 2097152 bytes)
[    0.000000] c0     0 Inode-cache hash table entries: 131072 (order: 8, 1048576 bytes)
[    0.000000] c0     0 software IO TLB [mem 0xffe10000-0xffe50000] (0MB) mapped at [ffffffc07fe10000-ffffffc07fe4ffff]
[    0.000000] c0     0 Memory: 1854412K/2096896K available (10736K kernel code, 1443K rwdata, 3480K rodata, 4936K init, 3812K bss, 242484K reserved, 0K cma-reserved)
[    0.000000] c0     0 Virtual kernel memory layout:
[    0.000000] c0     0     modules : 0xffffff8000000000 - 0xffffff8008000000   (   128 MB)
[    0.000000] c0     0     vmalloc : 0xffffff8008000000 - 0xffffffbdbfff0000   (   246 GB)
[    0.000000] c0     0       .init : 0xffffff8008e67000 - 0xffffff8009339000   (  4936 KB)
[    0.000000] c0     0       .text : 0xffffff8008080000 - 0xffffff8008afd000   ( 10740 KB)
[    0.000000] c0     0     .rodata : 0xffffff8008afd000 - 0xffffff8008e67000   (  3496 KB)
[    0.000000] c0     0       .data : 0xffffff8009339000 - 0xffffff80094a1fe0   (  1444 KB)
[    0.000000] c0     0     vmemmap : 0xffffffbdc0000000 - 0xffffffbfc0000000   (     8 GB maximum)
[    0.000000] c0     0               0xffffffbdc0000000 - 0xffffffbdc1fff000   (    31 MB actual)
[    0.000000] c0     0     fixed   : 0xffffffbffe7fb000 - 0xffffffbffec00000   (  4116 KB)
[    0.000000] c0     0     PCI I/O : 0xffffffbffee00000 - 0xffffffbfffe00000   (    16 MB)
[    0.000000] c0     0 SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=8, Nodes=1
[    0.000000] c0     0 Preemptible hierarchical RCU implementation.
[    0.000000] c0     0         Build-time adjustment of leaf fanout to 64.
[    0.000000] c0     0 NR_IRQS:64 nr_irqs:64 0
[    0.000000] c0     0 GIC: Using split EOI/Deactivate mode
[    0.000000] c0     0 CPU0: found redistributor 0 region 0:0x0000000014040000
[    0.000000] c0     0 of_sprd_pll_clk_setup clk:clk_twpll parent:ext_26m reg_num:3 setup ok
[    0.000000] c0     0 of_sprd_pll_clk_setup clk:clk_lpll parent:clk_lpll_gate reg_num:3 setup ok
[    0.000000] c0     0 of_sprd_pll_clk_setup clk:clk_gpll parent:clk_gpll_gate reg_num:3 setup ok
[    0.000000] c0     0 of_sprd_pll_clk_setup clk:clk_isppll parent:clk_isppll_gate reg_num:3 setup ok
[    0.000000] c0     0 of_sprd_pll_clk_setup clk:clk_mpll0 parent:clk_mpll0_gate reg_num:3 setup ok
[    0.000000] c0     0 of_sprd_pll_clk_setup clk:clk_mpll1 parent:clk_mpll1_gate reg_num:3 setup ok
[    0.000000] c0     0 of_sprd_pll_clk_setup clk:clk_mpll2 parent:clk_mpll2_gate reg_num:3 setup ok
[    0.000000] c0     0 of_sprd_pll_clk_setup clk:clk_rpll parent:ext_26m reg_num:3 setup ok
[    0.000000] c0     0 of_sprd_pll_clk_setup clk:clk_dpll0 parent:clk_dpll0_gate reg_num:3 setup ok
[    0.000000] c0     0 of_sprd_pll_clk_setup clk:clk_dpll1 parent:clk_dpll1_gate reg_num:3 setup ok
[    0.000000] c0     0 bc_irq is 1,clock-frequency is 32768
[    0.000000] c0     0 sprd persistent clock init, base:0xffffff800994e020, freq:32768
[    0.000000] c0     0 Architected cp15 timer(s) running at 26.00MHz (phys).
[    0.000000] c0     0 clocksource: arch_sys_counter: mask: 0xffffffffffffff max_cycles: 0x5ff13d5a9, max_idle_ns: 440795202370 ns
[    0.000004] c0     0 sched_clock: 56 bits at 26MHz, resolution 38ns, wraps every 4398046511088ns
[    0.009235] c0     0 CPU0: Unknown IPI message 0xd
[    0.013993] Calibrating delay loop (skipped), value calculated using timer frequency.. 52.00 BogoMIPS (lpj=104000)
[    0.024260] c0     0 pid_max: default: 32768 minimum: 301
[    0.029801] c0     0 Security Framework initialized
[    0.034529] c0     0 SELinux:  Initializing.
[    0.038952] c0     0 SELinux:  Starting in permissive mode
[    0.044492] c0     0 Mount-cache hash table entries: 4096 (order: 3, 32768 bytes)
[    0.051812] c0     0 Mountpoint-cache hash table entries: 4096 (order: 3, 32768 bytes)
[    0.061609] c0     0 Initializing cgroup subsys freezer
[    0.066703] c0     0 Initializing cgroup subsys debug
[    0.071804] c0     0 ftrace: allocating 32778 entries in 129 pages
[    0.159934] c0     1 sched-energy: Energy-costs installed from DT, min_cap_cpu_mask: 0-3
[    0.167990] c0     1 CPU0: update cpu_capacity 782
[    0.172893] c0     1 ASID allocator initialised with 32768 entries
[    0.219811] c1     0 Detected VIPT I-cache on CPU1
[    0.219837] c1     0 CPU1: found redistributor 100 region 0:0x0000000014060000
[    0.219882] c1     0 CPU1: update cpu_capacity 782
[    0.219887] c1     0 CPU1: Booted secondary processor [411fd050]
[    0.231860] c2     0 Detected VIPT I-cache on CPU2
[    0.231883] c2     0 CPU2: found redistributor 200 region 0:0x0000000014080000
[    0.231921] c2     0 CPU2: update cpu_capacity 782
[    0.231925] c2     0 CPU2: Booted secondary processor [411fd050]
[    0.243881] c3     0 Detected VIPT I-cache on CPU3
[    0.243901] c3     0 CPU3: found redistributor 300 region 0:0x00000000140a0000
[    0.243937] c3     0 CPU3: update cpu_capacity 782
[    0.243941] c3     0 CPU3: Booted secondary processor [411fd050]
[    0.255873] c4     0 Detected VIPT I-cache on CPU4
[    0.255889] c4     0 CPU4: found redistributor 400 region 0:0x00000000140c0000
[    0.255921] c4     0 CPU4: update cpu_capacity 1024
[    0.255924] c4     0 CPU4: Booted secondary processor [411fd050]
[    0.267965] c5     0 Detected VIPT I-cache on CPU5
[    0.267981] c5     0 CPU5: found redistributor 500 region 0:0x00000000140e0000
[    0.268013] c5     0 CPU5: update cpu_capacity 1024
[    0.268016] c5     0 CPU5: Booted secondary processor [411fd050]
[    0.280061] c6     0 Detected VIPT I-cache on CPU6
[    0.280077] c6     0 CPU6: found redistributor 600 region 0:0x0000000014100000
[    0.280107] c6     0 CPU6: update cpu_capacity 1024
[    0.280110] c6     0 CPU6: Booted secondary processor [411fd050]
[    0.292095] c7     0 Detected VIPT I-cache on CPU7
[    0.292111] c7     0 CPU7: found redistributor 700 region 0:0x0000000014120000
[    0.292141] c7     0 CPU7: update cpu_capacity 1024
[    0.292144] c7     0 CPU7: Booted secondary processor [411fd050]
[    0.292242] c0     1 Brought up 8 CPUs
[    0.455360] c0     1 SMP: Total of 8 processors activated.
[    0.460837] c0     1 CPU features: detected feature: GIC system register CPU interface
[    0.468730] c0     1 CPU features: detected feature: Privileged Access Never
[    0.475757] c0     1 CPU features: detected feature: LSE atomic instructions
[    0.482786] c0     1 CPU features: detected feature: User Access Override
[    0.489581] c0     1 CPU: All CPU(s) started at EL2
[    0.494362] c0    10 alternatives: patching kernel code
[    0.502565] c0     1 CPU7: update max cpu_capacity 1024
[    0.505826] c1     0 CPU1: update max cpu_capacity 782
[    0.513824] c7     0 CPU7: update max cpu_capacity 1024
[    0.524844] c4     1 devtmpfs: initialized
[    0.787825] c4     1 Initilizing CustomIPI irq domain
[    0.794407] c4     1 clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041785100000 ns
[    0.804871] c4     1 futex hash table entries: 2048 (order: 6, 262144 bytes)
[    0.812881] c4     1 pinctrl core: initialized pinctrl subsystem
[    0.819444] c4     1 hwspin_lock_request_specific: hwspinlock 1 does not exist
[    0.826635] c4     1 [disp-pm-domain][adf][ disp_pm_domain_init] display power domain init ok!
[    0.838356] c4     1 NET: Registered protocol family 16
[    0.843925] c4     1 schedtune: init normalization constants...
[    0.849676] c4     1 schedtune: CLUSTER[0-3]      min_pwr:     0 max_pwr:     0
[    0.856960] c4     1 schedtune: CPU[0]            min_pwr:     0 max_pwr:   181
[    0.864246] c4     1 schedtune: CPU[1]            min_pwr:     0 max_pwr:   181
[    0.871534] c4     1 schedtune: CPU[2]            min_pwr:     0 max_pwr:   181
[    0.878822] c4     1 schedtune: CPU[3]            min_pwr:     0 max_pwr:   181
[    0.886111] c4     1 schedtune: CLUSTER[4-7]      min_pwr:    42 max_pwr:   179
[    0.893398] c4     1 schedtune: CPU[4]            min_pwr:     0 max_pwr:   352
[    0.900686] c4     1 schedtune: CPU[5]            min_pwr:     0 max_pwr:   352
[    0.907973] c4     1 schedtune: CPU[6]            min_pwr:     0 max_pwr:   352
[    0.915261] c4     1 schedtune: CPU[7]            min_pwr:     0 max_pwr:   352
[    0.922548] c4     1 schedtune: SYSTEM            min_pwr:    42 max_pwr:  2311
[    0.929837] c4     1 schedtune: using normalization constants mul: 3458309939 sh1: 1 sh2: 11
[    0.938339] c4     1 schedtune: verify normalization constants...
[    0.944325] c4     1 schedtune: max_pwr/2^0: 2269 => norm_pwr:  1024
[    0.950746] c4     1 schedtune: max_pwr/2^1: 1134 => norm_pwr:   511
[    0.957079] c4     1 schedtune: max_pwr/2^2:  567 => norm_pwr:   255
[    0.963413] c4     1 schedtune: max_pwr/2^3:  283 => norm_pwr:   127
[    0.969747] c4     1 schedtune: max_pwr/2^4:  141 => norm_pwr:    63
[    0.976080] c4     1 schedtune: max_pwr/2^5:   70 => norm_pwr:    31
[    0.982415] c4     1 schedtune: configured to support 5 boost groups
[    0.989413] c4     1 [sprd-adf][  display_class_init] display class register
[    0.996484] c4     1 =============================================================================
[    1.005346] c4     1 BUG kmalloc-512 (Not tainted): Object padding overwritten
[    1.012546] c4     1 -----------------------------------------------------------------------------
[    1.012546] c4     1 
[    1.023738] c4     1 Disabling lock debugging due to kernel taint
[    1.029726] c4     1 INFO: 0xffffffc07b8fefe9-0xffffffc07b8fefef. First byte 0x50 instead of 0x5a
[    1.038576] c4     1 INFO: Slab 0xffffffbdc1ee3e00 objects=32 used=32 fp=0x          (null) flags=0x4080
[    1.048118] c4     1 INFO: Object 0xffffffc07b8fec80 @offset=27776 fp=0xffffffc07b8fe880
[    1.048118] c4     1 
[    1.058445] c4     1 Redzone ffffffc07b8fec00: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[    1.068594] c4     1 Redzone ffffffc07b8fec10: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[    1.078746] c4     1 Redzone ffffffc07b8fec20: bb bb bb bb bb