Enable arm_global_timer for Zynq brakes boot
From: Sören Brinkmann <hidden>
Date: 2013-08-12 16:03:34
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On Fri, Aug 09, 2013 at 10:27:57AM -0700, Stephen Boyd wrote:
On 08/09, Daniel Lezcano wrote:quoted
yes, but at least the broadcast mechanism should send an IPI to cpu0 to wake it up, no ? As Stephen stated this kind of configuration should has never been tested before so the tick broadcast code is not handling this case properly IMHO.If you have a per-cpu tick device that isn't suffering from FEAT_C3_STOP why wouldn't you use that for the tick versus a per-cpu tick device that has FEAT_C3_STOP? It sounds like there is a bug in the preference logic or you should boost the rating of the arm global timer above the twd. Does this patch help? It should make the arm global timer the tick device and whatever the cadence timer you have into the broadcast device.
I finally got to test your patch. Unfortunately, it makes the system hang even earlier: Starting kernel ... Uncompressing Linux... done, booting the kernel. [ 0.000000] Booting Linux on physical CPU 0x0 [ 0.000000] Linux version 3.11.0-rc3-00002-g391ac9b (sorenb at xsjandreislx) (gcc version 4.7.2 (Sourcery CodeBench Lite 2012.09-104) ) #98 SMP PREEMPT Mon Aug 12 08:59:34 PDT 2013 [ 0.000000] CPU: ARMv7 Processor [413fc090] revision 0 (ARMv7), cr=18c5387d [ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache [ 0.000000] Machine: Xilinx Zynq Platform, model: Zynq ZC706 Development Board [ 0.000000] bootconsole [earlycon0] enabled [ 0.000000] cma: CMA: reserved 16 MiB at 2e800000 [ 0.000000] Memory policy: ECC disabled, Data cache writealloc [ 0.000000] PERCPU: Embedded 9 pages/cpu @c149c000 s14720 r8192 d13952 u36864 [ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 260624 [ 0.000000] Kernel command line: console=ttyPS0,115200 earlyprintk [ 0.000000] PID hash table entries: 4096 (order: 2, 16384 bytes) [ 0.000000] Dentry cache hash table entries: 131072 (order: 7, 524288 bytes) [ 0.000000] Inode-cache hash table entries: 65536 (order: 6, 262144 bytes) [ 0.000000] Memory: 1004928K/1048576K available (4891K kernel code, 307K rwdata, 1564K rodata, 338K init, 5699K bss, 43648K reserved, 270336K highmem) [ 0.000000] Virtual kernel memory layout: [ 0.000000] vector : 0xffff0000 - 0xffff1000 ( 4 kB) [ 0.000000] fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB) [ 0.000000] vmalloc : 0xf0000000 - 0xff000000 ( 240 MB) [ 0.000000] lowmem : 0xc0000000 - 0xef800000 ( 760 MB) [ 0.000000] pkmap : 0xbfe00000 - 0xc0000000 ( 2 MB) [ 0.000000] modules : 0xbf000000 - 0xbfe00000 ( 14 MB) [ 0.000000] .text : 0xc0008000 - 0xc0656128 (6457 kB) [ 0.000000] .init : 0xc0657000 - 0xc06ab980 ( 339 kB) [ 0.000000] .data : 0xc06ac000 - 0xc06f8c20 ( 308 kB) [ 0.000000] .bss : 0xc06f8c20 - 0xc0c89aa4 (5700 kB) [ 0.000000] Preemptible hierarchical RCU implementation. [ 0.000000] RCU lockdep checking is enabled. [ 0.000000] Additional per-CPU info printed with stalls. [ 0.000000] RCU restricting CPUs from NR_CPUS=4 to nr_cpu_ids=2. [ 0.000000] NR_IRQS:16 nr_irqs:16 16 [ 0.000000] slcr mapped to f0004000 [ 0.000000] Zynq clock init [ 0.000000] sched_clock: 32 bits at 333MHz, resolution 3ns, wraps every 12884ms [ 0.000000] ttc0 #0 at f0006000, irq=43 [ 0.000000] Console: colour dummy device 80x30 [ 0.000000] Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar [ 0.000000] ... MAX_LOCKDEP_SUBCLASSES: 8 [ 0.000000] ... MAX_LOCK_DEPTH: 48 [ 0.000000] ... MAX_LOCKDEP_KEYS: 8191 [ 0.000000] ... CLASSHASH_SIZE: 4096 [ 0.000000] ... MAX_LOCKDEP_ENTRIES: 16384 [ 0.000000] ... MAX_LOCKDEP_CHAINS: 32768 [ 0.000000] ... CHAINHASH_SIZE: 16384 [ 0.000000] memory used by lock dependency info: 3695 kB [ 0.000000] per task-struct memory footprint: 1152 bytes [ 0.057541] Calibrating delay loop... 1325.46 BogoMIPS (lpj=6627328) [ 0.100248] pid_max: default: 32768 minimum: 301 [ 0.103294] Mount-cache hash table entries: 512 [ 0.114364] CPU: Testing write buffer coherency: ok [ 0.114513] ftrace: allocating 16143 entries in 48 pages [ 0.155012] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000 S?ren