Hi,

+ Thomas Gleixner

On Tue, Oct 16, 2012 at 06:28:13PM +0530, Shubhrajyoti Datta wrote:

On Mon, Oct 15, 2012 at 7:21 AM, Paul Walmsley [off-list ref] wrote:

quoted

Commit 3b2f8f82dad7d1f79cdc8fc05bd1c94baf109bde ("i2c: omap: switch to
threaded IRQ support") causes communication with I2C devices to fail
after system suspend/resume on all OMAP3 devices:

Could you tell me which  omap3 platform

On Beagle Xm
after
mount /dev/mmcblk  /mmcfs


# mount /dev/mmcblk0p2 /mmcfs/
[  412.480041] kjournald starting.  Commit interval 5 seconds
[  412.490020] EXT3-fs (mmcblk0p2): using internal journal
[  412.495605] EXT3-fs (mmcblk0p2): mounted filesystem with ordered data mode
#


# cd /mmcfs/
#
#
# ls
bin                   omap3_usb_prcm.sh     usb_prcm.sh
dev                   omap3_usbhs_off.sh    usb_uhh_show.sh
etc                   omap3_usbhs_on.sh     usb_uhh_tll.sh
init                  proc                  usbhs_clk_disable.sh
lib                   readmem.dat           usbhs_clk_enable.sh
lost+found            root                  usbhs_set_sm.sh
mnt                   sbin                  usbhs_show.sh
modules               sys                   usr
msc                   tmp                   var
omap3_ehcidump.sh     usb_omap3.sh
#
#
# echo mem > /sys/power/state
[  464.785461] PM: Syncing filesystems ... done.
[  464.791442] PM: Preparing system for mem sleep
[  464.798034] Freezing user space processes ... (elapsed 0.02 seconds) done.
[  464.827301] Freezing remaining freezable tasks ... (elapsed 0.02
seconds) done.
[  464.858703] PM: Entering mem sleep
[  464.862304] Suspending console(s) (use no_console_suspend to debug)
[  464.994415] PM: suspend of devices complete after 121.002 msecs
[  464.998107] PM: late suspend of devices complete after 3.662 msecs
[  465.003173] PM: noirq suspend of devices complete after 5.004 msecs
[  465.003173] Disabling non-boot CPUs ...
[  466.225585] Successfully put all powerdomains to target state
[  466.228942] PM: noirq resume of devices complete after 3.051 msecs
[  466.232421] PM: early resume of devices complete after 2.349 msecs
[  467.492645] PM: resume of devices complete after 1260.131 msecs
[  467.546936] PM: Finishing wakeup.
[  467.550415] Restarting tasks ... done.
#
#
# cat /debug/pm_debug/count | grep per_pwrdm
per_pwrdm (ON),OFF:7,RET:0,INA:0,ON:8,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
per_clkdm->per_pwrdm (17)
# echo mem > /sys/power/state
[ 1492.225311] PM: Syncing filesystems ... done.
[ 1492.232177] PM: Preparing system for mem sleep
[ 1492.238830] Freezing user space processes ... (elapsed 0.02 seconds) done.
[ 1492.268188] Freezing remaining freezable tasks ... (elapsed 0.02
seconds) done.
[ 1492.299804] PM: Entering mem sleep
[ 1492.303375] Suspending console(s) (use no_console_suspend to debug)
[ 1492.435333] PM: suspend of devices complete after 120.880 msecs
[ 1492.439025] PM: late suspend of devices complete after 3.692 msecs
[ 1492.444091] PM: noirq suspend of devices complete after 5.004 msecs
[ 1492.444091] Disabling non-boot CPUs ...
[ 1493.745544] Successfully put all powerdomains to target state
[ 1493.748901] PM: noirq resume of devices complete after 3.051 msecs
[ 1493.752319] PM: early resume of devices complete after 2.319 msecs
[ 1494.794067] PM: resume of devices complete after 1041.625 msecs
[ 1494.848388] PM: Finishing wakeup.
[ 1494.851867] Restarting tasks ... done.
#
#
# cat /debug/pm_debug/count | grep per_pwrdm
per_pwrdm (ON),OFF:8,RET:0,INA:0,ON:9,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
per_clkdm->per_pwrdm (17)
#

Anyways will retry with fs on mmc.

rootfs has to be on MMC to trigger this. The problem happens because
omap_hsmmc calls enable_irq() on its resume method. That IRQ line is
actually a GPIO from TWL4030, so
twl4030-irq.c::twl4030_sih_bus_sync_unlock() will be called, which will
trigger an I2C transfer.

The problem I see is that even though we properly return IRQ_WAKE_THREAD
and wake_up_process() manages to wakeup the IRQ thread (it returns 1),
the thread is never scheduled. To make things even worse, ouw irq thread
runs once, but doesn't run on a consecutive call. Here's some (rather
nasty) debug prints showing the problem:

[   78.709381] omap_i2c omap_i2c.1: omap_i2c_isr_thread 913
[   78.715026] omap_i2c omap_i2c.1: omap_i2c_isr_thread 1038
[   78.720733] omap_i2c omap_i2c.1: omap_i2c_xfer 655
[   78.725769] omap_i2c omap_i2c.1: omap_i2c_xfer 659
[   78.730804] omap_i2c omap_i2c.1: omap_i2c_xfer 663
[   78.735870] omap_i2c omap_i2c.1: omap_i2c_xfer 668
[   78.850708] PM: suspend of devices complete after 1287.841 msecs
[   78.860870] PM: late suspend of devices complete after 3.753 msecs
[   78.872283] try_to_wake_up 1411
[   78.875701] try_to_wake_up 1411
[   78.879028] try_to_wake_up 1411
[   78.882537] omap_i2c omap_i2c.1: omap_i2c_runtime_suspend 1359
[   78.888763] omap_i2c omap_i2c.1: omap_i2c_low_level_suspend 1261
[   78.895416] PM: noirq suspend of devices complete after 28.015 msecs
[   78.902160] Disabling non-boot CPUs ...
[   88.568664] Powerdomain (per_pwrdm) didn't enter target state 1
[   88.574859] Powerdomain (core_pwrdm) didn't enter target state 1
[   88.581115] Could not enter target state in pm_suspend
[   88.586975] omap_i2c omap_i2c.1: omap_i2c_runtime_resume 1373
[   88.592987] omap_i2c omap_i2c.1: omap_i2c_low_level_resume 1287
[   88.599243] try_to_wake_up 1411
[   88.602569] try_to_wake_up 1411
[   88.608459] PM: noirq resume of devices complete after 21.759 msecs
[   88.615814] try_to_wake_up 1411
[   88.622497] PM: early resume of devices complete after 2.380 msecs
[   88.632965] omap_i2c omap_i2c.1: omap_i2c_xfer 626
[   88.638092] omap_i2c omap_i2c.1: omap_i2c_xfer 632
[   88.643188] omap_i2c omap_i2c.1: omap_i2c_xfer 648
[   88.648193] omap_i2c omap_i2c.1: addr: 0x0049, len: 4, flags: 0x0, stop: 1
[   88.655456] omap_i2c omap_i2c.1: omap_i2c_xfer_msg 537
[   88.660858] omap_i2c omap_i2c.1: omap_i2c_isr 885
[   88.665802] omap_i2c omap_i2c.1: omap_i2c_isr 891: mask 601f stat 1510
[   88.672637] omap_i2c omap_i2c.1: omap_i2c_isr 894
[   88.677551] omap_i2c omap_i2c.1: omap_i2c_isr 899
[   88.682495] ===> irq_wake_thread 139: IRQ 72 wake_up_process 1
[   88.688751] omap_i2c omap_i2c.1: omap_i2c_isr_thread 913
[   88.694335] omap_i2c omap_i2c.1: omap_i2c_isr_thread 1038
[   88.700347] omap_i2c omap_i2c.1: omap_i2c_isr 885
[   88.705291] omap_i2c omap_i2c.1: omap_i2c_isr 891: mask 601f stat 0104
[   88.712097] omap_i2c omap_i2c.1: omap_i2c_isr 894
[   88.717010] omap_i2c omap_i2c.1: omap_i2c_isr 899
[   88.721923] try_to_wake_up 1411
[   88.725189] ===> irq_wake_thread 139: IRQ 72 wake_up_process 0
[   88.731292] [sched_delayed] sched: RT throttling activated
[   88.737091] omap_i2c omap_i2c.1: omap_i2c_isr_thread 913
[   88.742706] omap_i2c omap_i2c.1: omap_i2c_isr_thread 1038

this is the last time our omap_i2c_isr_thread() runs. Note that the
thread was already running when wake_up_process() was called.

[   88.749206] omap_i2c omap_i2c.1: omap_i2c_xfer 655
[   88.754302] omap_i2c omap_i2c.1: omap_i2c_xfer 659
[   88.759368] omap_i2c omap_i2c.1: omap_i2c_xfer 663
[   88.764373] omap_i2c omap_i2c.1: omap_i2c_xfer 668
[   88.769531] omap_i2c omap_i2c.1: omap_i2c_xfer 626
[   88.774597] omap_i2c omap_i2c.1: omap_i2c_xfer 632
[   88.779602] omap_i2c omap_i2c.1: omap_i2c_xfer 648
[   88.784667] omap_i2c omap_i2c.1: addr: 0x004b, len: 1, flags: 0x0, stop: 0
[   88.791900] omap_i2c omap_i2c.1: omap_i2c_xfer_msg 537
[   88.797271] omap_i2c omap_i2c.1: omap_i2c_isr 885
[   88.802185] omap_i2c omap_i2c.1: omap_i2c_isr 891: mask 601f stat 1510
[   88.809020] omap_i2c omap_i2c.1: omap_i2c_isr 894
[   88.813934] omap_i2c omap_i2c.1: omap_i2c_isr 899
[   88.818847] ===> irq_wake_thread 139: IRQ 72 wake_up_process 1

notice here that our omap_i2c_isr_thread() never runs. I'm still
debugging, trying to pin point what the real issue is, but it's
definitely not the fact that we have a threaded ISR, since it runs at
least once.

[   90.610107] try_to_wake_up 1411
[   93.821044] try_to_wake_up 1411
[   93.824768] omap_i2c omap_i2c.1: controller timed out
[   93.830169] [<c001c118>] (unwind_backtrace+0x0/0xf0) from [<c040c738>] (omap_i2c_xfer_msg+0x314/0x360)
[   93.839935] [<c040c738>] (omap_i2c_xfer_msg+0x314/0x360) from [<c040d26c>] (omap_i2c_xfer+0xac/0x220)
[   93.849639] [<c040d26c>] (omap_i2c_xfer+0xac/0x220) from [<c040884c>] (__i2c_transfer+0x40/0x80)
[   93.858886] [<c040884c>] (__i2c_transfer+0x40/0x80) from [<c0409da8>] (i2c_transfer+0x1f8/0x26c)
[   93.868103] [<c0409da8>] (i2c_transfer+0x1f8/0x26c) from [<c035dab8>] (twl_i2c_read+0xc4/0x15c)
[   93.877288] [<c035dab8>] (twl_i2c_read+0xc4/0x15c) from [<c03189f4>] (twl4030ldo_get_voltage+0x28/0x60)
[   93.887145] [<c03189f4>] (twl4030ldo_get_voltage+0x28/0x60) from [<c03120b0>] (_regulator_get_voltage+0x68/0x84)
[   93.897827] [<c03120b0>] (_regulator_get_voltage+0x68/0x84) from [<c03125a0>] (regulator_get_voltage+0x20/0x38)
[   93.908447] [<c03125a0>] (regulator_get_voltage+0x20/0x38) from [<c0411bcc>] (mmc_regulator_set_ocr+0x40/0x12c)
[   93.919036] [<c0411bcc>] (mmc_regulator_set_ocr+0x40/0x12c) from [<c0426418>] (omap_hsmmc_set_power+0xe4/0x11c)
[   93.929626] [<c0426418>] (omap_hsmmc_set_power+0xe4/0x11c) from [<c042582c>] (omap_hsmmc_set_ios+0x140/0x150)
[   93.940032] [<c042582c>] (omap_hsmmc_set_ios+0x140/0x150) from [<c04135c4>] (mmc_power_up+0x80/0xc4)
[   93.949615] [<c04135c4>] (mmc_power_up+0x80/0xc4) from [<c04136d8>] (mmc_resume_host+0xd0/0x150)
[   93.958862] [<c04136d8>] (mmc_resume_host+0xd0/0x150) from [<c0426b5c>] (omap_hsmmc_resume+0x7c/0xc8)
[   93.968536] [<c0426b5c>] (omap_hsmmc_resume+0x7c/0xc8) from [<c0347a78>] (platform_pm_resume+0x2c/0x50)
[   93.978424] [<c0347a78>] (platform_pm_resume+0x2c/0x50) from [<c034bca4>] (dpm_run_callback.isra.4+0x2c/0x64)
[   93.988830] [<c034bca4>] (dpm_run_callback.isra.4+0x2c/0x64) from [<c034ca48>] (device_resume+0xdc/0x18c)
[   93.998870] [<c034ca48>] (device_resume+0xdc/0x18c) from [<c034ce8c>] (dpm_resume+0xfc/0x21c)
[   94.007812] [<c034ce8c>] (dpm_resume+0xfc/0x21c) from [<c034d094>] (dpm_resume_end+0xc/0x18)
[   94.016723] [<c034d094>] (dpm_resume_end+0xc/0x18) from [<c0087b14>] (suspend_devices_and_enter+0xe8/0x1b0)
[   94.026947] [<c0087b14>] (suspend_devices_and_enter+0xe8/0x1b0) from [<c0087c78>] (enter_state+0x9c/0xdc)
[   94.036987] [<c0087c78>] (enter_state+0x9c/0xdc) from [<c0087ccc>] (pm_suspend+0x14/0x70)
[   94.045593] [<c0087ccc>] (pm_suspend+0x14/0x70) from [<c0086d34>] (state_store+0x30/0x3c)
[   94.054199] [<c0086d34>] (state_store+0x30/0x3c) from [<c02d39b8>] (kobj_attr_store+0x14/0x20)
[   94.063262] [<c02d39b8>] (kobj_attr_store+0x14/0x20) from [<c017bcd0>] (sysfs_write_file+0x80/0xb4)
[   94.072784] [<c017bcd0>] (sysfs_write_file+0x80/0xb4) from [<c01174c4>] (vfs_write+0xa8/0x138)
[   94.081817] [<c01174c4>] (vfs_write+0xa8/0x138) from [<c0117730>] (sys_write+0x40/0x68)
[   94.090240] [<c0117730>] (sys_write+0x40/0x68) from [<c0013f40>] (ret_fast_syscall+0x0/0x3c)
[   94.099334] omap_i2c omap_i2c.1: omap_i2c_xfer 655
[   94.104431] omap_i2c omap_i2c.1: omap_i2c_xfer 659
[   94.109466] omap_i2c omap_i2c.1: omap_i2c_xfer 663
[   94.114532] omap_i2c omap_i2c.1: omap_i2c_xfer 668
[   94.119567] twl: i2c_read failed to transfer all messages
[   94.125244] omap_hsmmc omap_hsmmc.0: could not set regulator OCR (-110)
[   94.286773] mmc0: error -110 during resume (card was removed?)

-- 
balbi
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