Re: ACPI errors with 3.7-rc3

[Feng Tang <feng.tang@intel.com>]

On Fri, Nov 09, 2012 at 10:30:43PM +0800, Moore, Robert wrote:
> The ACPI Global Lock is in fact intended to provide exclusion between the BIOS and the OS.
> Bob

Thanks for the info.

And per my check, most of ACPI FW don't implement this lock, say
after driver probe, the ec->global_lock will be 0.

- Feng

> 
> 
> > -----Original Message-----
> > From: Tang, Feng
> > Sent: Friday, November 09, 2012 1:29 AM
> > To: Rafael J. Wysocki
> > Cc: Greg KH; Azat Khuzhin; linux-acpi@vger.kernel.org; Linux Kernel
> > Mailing List; Zheng, Lv; Len Brown; Moore, Robert
> > Subject: Re: ACPI errors with 3.7-rc3
> > 
> > On Thu, Nov 08, 2012 at 05:49:40AM +0800, Rafael J. Wysocki wrote:
> > > On Tuesday, November 06, 2012 01:48:26 PM Greg KH wrote:
> > > > On Tue, Nov 06, 2012 at 04:42:24PM +0400, Azat Khuzhin wrote:
> > > > > I'v also have such errors on my macbook pro.
> > > > >
> > > > > $ dmesg | tail
> > > > > [17056.008564] ACPI Error: Method parse/execution failed
> > > > > [\_SB_.PCI0.LPCB.EC__.SMB0.SBRW] (Node ffff88026547ea10), AE_TIME
> > > > > (20120711/psparse-536)
> > > > > [17056.011194] ACPI Error: Method parse/execution failed
> > > > > [\_SB_.BAT0.UBST] (Node ffff88026547e678), AE_TIME
> > > > > (20120711/psparse-536)
> > > > > [17056.013793] ACPI Error: Method parse/execution failed
> > > > > [\_SB_.BAT0._BST] (Node ffff88026547e740), AE_TIME
> > > > > (20120711/psparse-536)
> > > > > [17056.016383] ACPI Exception: AE_TIME, Evaluating _BST
> > > > > (20120711/battery-464) [17056.511373] ACPI: EC: input buffer is
> > > > > not empty, aborting transaction [17056.512672] ACPI Exception:
> > > > > AE_TIME, Returned by Handler for [EmbeddedControl]
> > > > > (20120711/evregion-501) [17056.515256] ACPI Error: Method
> > > > > parse/execution failed [\_SB_.PCI0.LPCB.EC__.SMB0.SBRW] (Node
> > > > > ffff88026547ea10), AE_TIME
> > > > > (20120711/psparse-536)
> > > > > [17056.517886] ACPI Error: Method parse/execution failed
> > > > > [\_SB_.BAT0.UBST] (Node ffff88026547e678), AE_TIME
> > > > > (20120711/psparse-536)
> > > > > [17056.520479] ACPI Error: Method parse/execution failed
> > > > > [\_SB_.BAT0._BST] (Node ffff88026547e740), AE_TIME
> > > > > (20120711/psparse-536)
> > > > > [17056.523070] ACPI Exception: AE_TIME, Evaluating _BST
> > > > > (20120711/battery-464)
> > > >
> > > > I'm seeing this again right now.  I'm wondering if it's because I'm
> > > > running on battery power at the moment:
> > > >
> > > > [41694.309264] ACPI Exception: AE_TIME, Returned by Handler for
> > > > [EmbeddedControl] (20120913/evregion-501) [41694.309282] ACPI Error:
> > > > Method parse/execution failed [\_SB_.PCI0.LPCB.EC__.SMB0.SBRW] (Node
> > > > ffff88045cc64618), AE_TIME (20120913/psparse-536) [41694.309300]
> > > > ACPI Error: Method parse/execution failed [\_SB_.BAT0.UBST] (Node
> > > > ffff88045cc64988), AE_TIME (20120913/psparse-536) [41694.309310]
> > > > ACPI Error: Method parse/execution failed [\_SB_.BAT0._BST] (Node
> > > > ffff88045cc648c0), AE_TIME (20120913/psparse-536) [41694.309324]
> > > > ACPI Exception: AE_TIME, Evaluating _BST (20120913/battery-464)
> > > > [41694.809093] ACPI: EC: input buffer is not empty, aborting
> > > > transaction
> > > >
> > > > ec_storm_threshold is still set to 8 in /sys/module/acpi/parameters/
> > > > so that's not the issue here.
> > > >
> > > > > And also loadavg is too high ~ 10
> > > > > While there is no process that load CPU up to 100% or like that.
> > > > > I think that this because of processes that is done in kernel space.
> > > > > (basically that one who write such errors)
> > > > >
> > > > > $ uname -a
> > > > > Linux macbook-pro-sq 3.6.5macbook-pro-custom-v0.1 #4 SMP Sun Nov 4
> > > > > 12:39:03 UTC 2012 x86_64 GNU/Linux
> > > >
> > > > Ah, ok, that means it's not something new in 3.7-rc, so maybe it's
> > > > just never worked properly for this hardware :)
> > > >
> > > > So it's not a regression, just an ACPI issue, any ACPI developer
> > > > have an idea about this?
> > >
> > > Can you please send the output of acpidump from the affected machine(s)?
> > 
> > I doubt this problem is sometimes inevitable for some machines, because
> > AFAIK most modern machines have the race problem for EC HW controller, as
> > both OS side and the BIOS may access the EC HW at the same time
> > without any race control.
> > 
> > For this case, usually the battery and thermal modules (which may be
> > controlled through EC) are always monitored by BIOS, when OS also
> > frequently visit them too, the EC's own state machine may be broken and
> > not responsive due to the race, then cause the timeout error.
> > And how severe the problem will be depends on the EC HW, the quality of
> > BIOS code and OS/driver code.
> > 
> > Myself have seen the similar "ACPI: EC: input buffer is not empty,
> > aborting transaction" error message on one laptop when its EC is busy
> > visited by OS.
> > 
> > btw, in EC driver I see a "ec->global_lock", don't know if it was designed
> > to control the race between OS and BIOS.
> > 
> > Thanks,
> > Feng