On Thu, Jul 09, 2009 at 05:44:52PM +0200, Marcin Slusarz wrote:
> I find this message after resume from s2ram:
> [ 133.014802] ------------[ cut here ]------------
> [ 133.014814] WARNING: at drivers/base/sys.c:411 sysdev_suspend+0xd3/0x27b()
> [ 133.014819] Hardware name: To Be Filled By O.E.M.
> [ 133.014828] Interrupts enabled after cpufreq_suspend+0x0/0xfd
> [ 133.014832] Modules linked in:
> [ 133.014840] Pid: 6569, comm: s2ram Not tainted 2.6.31-rc2-faf80-wusb54gc #139
> [ 133.014845] Call Trace:
> [ 133.014853] [<ffffffff8126960a>] ? sysdev_suspend+0xd3/0x27b
> [ 133.014864] [<ffffffff810388a9>] warn_slowpath_common+0x77/0xa4
> [ 133.014873] [<ffffffff8103894b>] warn_slowpath_fmt+0x64/0x66
> [ 133.014883] [<ffffffff8101ac71>] ? query_values_on_cpu+0x0/0x19
> [ 133.014892] [<ffffffff813273bc>] ? cpufreq_suspend+0x0/0xfd
> [ 133.014900] [<ffffffff811e6d35>] ? kobject_put+0x47/0x4b
> [ 133.014908] [<ffffffff813269fd>] ? cpufreq_cpu_put+0x1f/0x21
> [ 133.014917] [<ffffffff813274ac>] ? cpufreq_suspend+0xf0/0xfd
> [ 133.014926] [<ffffffff8105aeda>] ? trace_hardirqs_off+0xd/0xf
> [ 133.014934] [<ffffffff8126960a>] sysdev_suspend+0xd3/0x27b
> [ 133.014944] [<ffffffff81068fd8>] suspend_devices_and_enter+0xca/0x14d
> [ 133.014952] [<ffffffff81069114>] enter_state+0xb9/0xec
> [ 133.014959] [<ffffffff81068923>] state_store+0xb7/0xd7
> [ 133.014967] [<ffffffff811e6b4b>] kobj_attr_store+0x17/0x19
> [ 133.014976] [<ffffffff811094b1>] sysfs_write_file+0xe4/0x119
> [ 133.014985] [<ffffffff810b9f57>] vfs_write+0xac/0x164
> [ 133.014991] [<ffffffff810ba0d3>] sys_write+0x47/0x6e
> [ 133.015000] [<ffffffff8100aee8>] system_call_fastpath+0x16/0x1b
> [ 133.015006] ---[ end trace 470f36a1cfb444d7 ]---
powernow-k8's ->get is calling smp_call_function_single which enables interrupts.
So I couldn't help wondering... why are we caring so much about the current cpu
speed when we ->suspend anyway ? Why is cpufreq_suspend doing those gymnastics at all,
instead of just doing nothing at suspend time, and just setting the frequency
to maximum speed on resume ?
The answer seems to be in 42d4dc3f4e1ec1396371aac89d0dccfdd977191b
which introduced all this code to work around some failure that only happens
on PPC...
[PATCH] Add suspend method to cpufreq core
In order to properly fix some issues with cpufreq vs. sleep on
PowerBooks, I had to add a suspend callback to the pmac_cpufreq driver.
I must force a switch to full speed before sleep and I switch back to
previous speed on resume.
Ben, is there something better we can do here ?
I really don't want to add an #ifdef __powerpc__ to core code if we can help it.
I'd rather we didn't call into driver guts at all from the suspend path.
Dave
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