[haiku-bugs] Re: [Haiku] #5838: Enabled ACPI , but cant install Battery Bar Replicant in tray.

From: "phoudoin" <trac@xxxxxxxxxxxx>
Date: Thu, 06 May 2010 23:04:40 -0000

#5838: Enabled ACPI , but cant install Battery Bar Replicant in tray.
--------------------------+-------------------------------------------------
 Reporter:  streak        |       Owner:  czeidler      
     Type:  bug           |      Status:  assigned      
 Priority:  normal        |   Milestone:  R1/alpha2     
Component:  Drivers/ACPI  |     Version:  R1/Development
 Keywords:                |   Blockedby:                
 Platform:  All           |    Blocking:                
--------------------------+-------------------------------------------------

Comment(by phoudoin):

 > Not sure what you're talking about here.

 Me neither, anymore :-)

 > To my knowledge MSRs always have fixed indexes.

 True.
 But on multi-CPUs, the driver should read & write the good registers,
 hence why ACPI 2.0 introduced the possibility to publish via _PCT object
 table memory mapped or IO addresses for these performance control & status
 registers, which allow a driver to modify them without having to run on
 the CPU. FreeBSD's acpi_perf.c and Linux's processor_perflib.c uses them
 when they're available.

 I suspect the enhanced_speedstep driver, assuming only one CPU, read or
 write perf MSRs on the wrong CPU, while only the one who ran est_open()
 have EST enabled, without any warranty they're the same one...

-- 
Ticket URL: <http://dev.haiku-os.org/ticket/5838#comment:19>
Haiku <http://dev.haiku-os.org>
Haiku - the operating system.

[haiku-bugs] Re: [Haiku] #5838: Enabled ACPI , but cant install Battery Bar Replicant in tray.

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