#7479 BLOC Never A: Suspend failing due to EC warning

[Zarro Boogs per Child]

#7479: Suspend failing due to EC warning
---------------------+------------------------------------------------------
 Reporter:  cjb      |         Owner:  dsaxena       
     Type:  defect   |        Status:  new           
 Priority:  blocker  |     Milestone:  Never Assigned
Component:  kernel   |       Version:  Update.1      
 Keywords:           |   Next_action:  diagnose      
 Verified:  0        |     Blockedby:                
 Blocking:           |  
---------------------+------------------------------------------------------
 Seen by the tinderbox's suspend tests, after 30 iterations:

 {{{
 [ 7718.043376] PM: Syncing filesystems ... done.
 [ 7718.044006] PM: Preparing system for mem sleep
 [ 7718.044279] Freezing user space processes ... (elapsed 0.10 seconds)
 done.
 [ 7718.147318] Freezing remaining freezable tasks ... (elapsed 0.14
 seconds) don
 e.
 [ 7718.286397] PM: Entering mem sleep
 [ 7718.286411] Suspending console(s)
 [ 7718.288083] ehci_bus_suspend: USBCMD: 0x10009
 [ 7718.288099] ehci_bus_suspend: USBSTS: 0x8
 [ 7718.288115] ehci_bus_suspend: USBCMD: 0x10009
 [ 7718.288129] ehci_bus_suspend: USBSTS: 0x8
 [ 7718.288834] ehci_bus_suspend: USBCMD: 0x10008
 [ 7718.288848] ehci_bus_suspend: USBSTS: 0x1008
 [ 7718.313483] ehci_pci_suspend: USBCMD: 0x10008
 [ 7718.313499] ehci_pci_suspend: USBSTS: 0x1008
 [ 7718.347360] olpc-ec:  running cmd 0x1c
 [ 7718.350390] olpc-ec:  received 0x7f
 [ 7718.350390] ------------[ cut here ]------------
 [ 7718.350390] WARNING: at arch/x86/kernel/olpc-pm.c:313
 olpc_ec_mask_unset+0x43/0x7c()
 [ 7718.350390] Modules linked in: sg usb8xxx libertas usb_storage libusual
 ieee80211 ieee80211_crypt pcspkr mousedev ehci_hcd ohci_hcd cs5535_gpio
 sdhci mmc_core usbcore
 [ 7718.350390] Pid: 1528, comm: bash Not tainted
 2.6.25-20080710.3.olpc.14813f826d6ccaf #1
 [ 7718.350390]  [<c041492b>] warn_on_slowpath+0x40/0x4f
 [ 7718.350390]  [<c05e5db2>] __down_trylock+0x3a/0x43
 [ 7718.350390]  [<c05eb7e7>] __down_failed_trylock+0x7/0xc
 [ 7718.350390]  [<c05ebc47>] _spin_unlock+0xf/0x22
 [ 7718.350390]  [<c04154b0>] vprintk+0x27d/0x2f7
 [ 7718.350390]  [<c0429c7d>] tick_notify+0x1e5/0x1ef
 [ 7718.350390]  [<c04da506>] delay_tsc+0x2c/0x43
 [ 7718.350390]  [<c041553e>] printk+0x14/0x18
 [ 7718.350390]  [<c05ebcb2>] _spin_unlock_irqrestore+0x14/0x29
 [ 7718.350390]  [<c0409c05>] olpc_ec_cmd+0x17d/0x188
 [ 7718.350390]  [<c0409fbb>] olpc_ec_mask_unset+0x43/0x7c
 [ 7718.350390]  [<c040a11e>] olpc_fixup_sleep+0x12a/0x141
 [ 7718.350390]  [<c040a347>] olpc_pm_enter+0x10/0x49
 [ 7718.350390]  [<c0430b99>] suspend_devices_and_enter+0xd8/0x118
 [ 7718.350390]  [<c0430d01>] enter_state+0x10a/0x179
 [ 7718.350390]  [<c0430e00>] state_store+0x90/0xa8
 [ 7718.350390]  [<c0430d70>] state_store+0x0/0xa8
 [ 7718.350390]  [<c04d6623>] kobj_attr_store+0x18/0x1c
 7718.350390]  [<c048b329>] sysfs_write_file+0x9f/0xd3
 [ 7718.350390]  [<c048b28a>] sysfs_write_file+0x0/0xd3
 [ 7718.350390]  [<c0456325>] vfs_write+0x83/0xfc
 [ 7718.350390]  [<c04567e1>] sys_write+0x3c/0x63
 [ 7718.350390]  [<c0403782>] sysenter_past_esp+0x5f/0x85
 [ 7718.350390]  =======================
 [ 7718.350390] ---[ end trace edd52afcef97ca53 ]---
 [ 7718.350390] olpc-ec:  running cmd 0x1b
 [ 7718.350390] olpc-ec:  sending cmd arg 0x3b
 [ 7718.350390] olpc-ec:  running cmd 0x32
 [ 7718.350390] olpc_do_sleep!
 }}}

 On the console, we see:

 {{{
 [1215734390.02] -bash-3.2# echo mem > /sys/power/state
 [1215734390.04] -bash: echo: write error: Device or resource busy
 }}}

 (It's possible that something else is causing the write error, but I can't
 see what it might be.  Full dmesg uploaded.)

-- 
Ticket URL: <http://dev.laptop.org/ticket/7479>
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