2.6.29-rcX: wierd iteractions with CPUFREQ

[Dmitry Torokhov]

Hi,

Something weird is happening with 2.6.29 - once my laptop starts heating
up and fans come up it locks at 800MHz, but there are no valid thermal
events. If I enable cpufreq debug I am getting the following (dump stack
was added by myself to see where __cpufreq_set_policy is being called from):

CPU0: setting new policy for CPU 0: 800000 - 2201000 kHz                                      
Pid: 220, comm: kacpi_notify Not tainted 2.6.29-rc8 #110
Call Trace:                                                                                   
 [<ffffffff812fd35e>] __cpufreq_set_policy+0x3a/0x210                                         
 [<ffffffff812fed87>] cpufreq_update_policy+0x112/0x134                                       
 [<ffffffff812feda9>] ? handle_update+0x0/0x38                                                
 [<ffffffff8121bde7>] acpi_processor_ppc_has_changed+0xc8/0xd1                                
 [<ffffffff8120f69d>] ? acpi_bus_get_device+0x2a/0x3e                                         
 [<ffffffff81218298>] acpi_processor_notify+0x64/0x10d                                        
 [<ffffffff814505bf>] ? _spin_unlock_irq+0x30/0x62                                            
 [<ffffffff811fae58>] acpi_ev_notify_dispatch+0x64/0x70                                       
 [<ffffffff811f46d2>] acpi_os_execute_deferred+0x31/0x3e                                      
 [<ffffffff8104e301>] run_workqueue+0x108/0x21b                                               
 [<ffffffff8104e2af>] ? run_workqueue+0xb6/0x21b                                              
 [<ffffffff811f46a1>] ? acpi_os_execute_deferred+0x0/0x3e                                     
 [<ffffffff8104e4f9>] worker_thread+0xe5/0xf6                                                 
 [<ffffffff81052599>] ? autoremove_wake_function+0x0/0x3d                                     
 [<ffffffff8104e414>] ? worker_thread+0x0/0xf6                                                
 [<ffffffff810521b8>] kthread+0x4e/0x7b                                                       
 [<ffffffff8100cb7a>] child_rip+0xa/0x20                                                      
 [<ffffffff81035d11>] ? finish_task_switch+0x0/0xca                                           
 [<ffffffff8100c540>] ? restore_args+0x0/0x30                                                 
 [<ffffffff8105216a>] ? kthread+0x0/0x7b                                                      
 [<ffffffff8100cb70>] ? child_rip+0x0/0x20                                                    
freq-table: request for verification of policy (800000 - 2201000 kHz) for cpu 0               
freq-table: verification lead to (800000 - 2201000 kHz) for cpu 0                             
freq-table: request for verification of policy (800000 - 800000 kHz) for cpu 0                
freq-table: verification lead to (800000 - 800000 kHz) for cpu 0                              
cpufreq-core: new min and max freqs are 800000 - 800000 kHz                                   
cpufreq-core: governor: change or update limits                                               
cpufreq-core: __cpufreq_governor for CPU 0, event 3                                           
cpufreq-core: target for CPU 0: 800000 kHz, relation 1                                        
freq-table: request for target 800000 kHz (relation: 1) for cpu 0
freq-table: target is 4 (800000 kHz, 4)
cpufreq-core: notification 0 of frequency transition to 800000 kHz
cpufreq-core: notification 1 of frequency transition to 800000 kHz

As you can see for some reason the 2nd validation clams the frequency to 800
(although the first one done immediately before says that 2.2GHz is fine)
and the system slows to a crawl.

-- 
Dmitry
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/