Quoting Stephen Warren (2012-09-13 10:26:34)

On 09/13/2012 09:57 AM, Stephen Warren wrote:

quoted

On 09/13/2012 03:34 AM, Prashant Gaikwad wrote:

quoted

Clockevent's frequency is changed upon cpufreq change
notification. It fetches local timer's rate to update the
clockevent frequency. This patch adds local timer clock
for Tegra20.

Hmm. Off-list, I'd asked you to check whether this patch, and Mike's
twd/clk-notifier changes were OK for Tegra, and part of your reponse was:

Tegra20 (Ventana)
        Tegra's for-next (common clock) + smp_twd : Panic

Is that true? If so, I can't apply this patch...

Oh, perhaps you mean the warning below? That's exactly the issue that
Mike's patch was intended to solve, so it's not surprising that it'd be
seen as soon as we actually implement the smp_twd clock. If that's all,
then it seems OK to apply this.

Can you confirm that the problem goes away with this patch:
http://article.gmane.org/gmane.linux.ports.arm.kernel/187488/match=

Thanks,
Mike

quoted

[    1.287406] ------------[ cut here ]------------
[    1.292049] WARNING: at kernel/mutex.c:198 __mutex_lock_slowpath+0x2c8/0x34c()
[    1.299259] Modules linked in:
[    1.302361] [<c0015118>] (unwind_backtrace+0x0/0x138) from [<c0027d3c>] (warn_slowpath_common+0x4c/0x64)
[    1.311843] [<c0027d3c>] (warn_slowpath_common+0x4c/0x64) from [<c0027d70>] (warn_slowpath_null+0x1c/0x24)
[    1.321497] [<c0027d70>] (warn_slowpath_null+0x1c/0x24) from [<c04a140c>] (__mutex_lock_slowpath+0x2c8/0x34c)
[    1.331412] [<c04a140c>] (__mutex_lock_slowpath+0x2c8/0x34c) from [<c04a149c>] (mutex_lock+0xc/0x24)
[    1.340551] [<c04a149c>] (mutex_lock+0xc/0x24) from [<c0306a04>] (clk_get_rate+0x10/0x68)
[    1.348731] [<c0306a04>] (clk_get_rate+0x10/0x68) from [<c00148a0>] (twd_update_frequency+0x14/0x48)
[    1.357865] [<c00148a0>] (twd_update_frequency+0x14/0x48) from [<c0070a58>] (generic_smp_call_function_single_interrupt+0xd0/0x130)
[    1.369686] [<c0070a58>] (generic_smp_call_function_single_interrupt+0xd0/0x130) from [<c00140c4>] (handle_IPI+0xb0/0x154)
[    1.380723] [<c00140c4>] (handle_IPI+0xb0/0x154) from [<c0008560>] (gic_handle_irq+0x54/0x5c)
[    1.389255] [<c0008560>] (gic_handle_irq+0x54/0x5c) from [<c000e9e0>] (__irq_svc+0x40/0x70)
[    1.397594] Exception stack(0xef083f50 to 0xef083f98)
[    1.402643] 3f40:                                     ef083fa0 00000000 00000000 000f4240
[    1.410815] 3f60: 00001093 00000000 00000000 c0f3d3d8 ef083f98 411fc090 00000000 00000000
[    1.418984] 3f80: 3b9ac9ff ef083f98 c01e4728 c001f010 20000013 ffffffff
[    1.425612] [<c000e9e0>] (__irq_svc+0x40/0x70) from [<c001f010>] (tegra_idle_enter_lp3+0x68/0x78)
[    1.434488] [<c001f010>] (tegra_idle_enter_lp3+0x68/0x78) from [<c02d80f8>] (cpuidle_enter+0x14/0x18)
[    1.443705] [<c02d80f8>] (cpuidle_enter+0x14/0x18) from [<c02d868c>] (cpuidle_idle_call+0xb0/0x140)
[    1.452752] [<c02d868c>] (cpuidle_idle_call+0xb0/0x140) from [<c000fb14>] (cpu_idle+0xbc/0x110)
[    1.461448] [<c000fb14>] (cpu_idle+0xbc/0x110) from [<0049d414>] (0x49d414)
[    1.468421] ---[ end trace bb3563806344f4a0 ]---

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