kern/150517: [acpi] acpi_ec does not work properly on Lenovo S10[e] (due to dynamic switching to polled mode)

Tue Oct 5 18:00:08 UTC 2010

The following reply was made to PR kern/150517; it has been noted by GNATS.

From: David Naylor <naylor.b.david at gmail.com>
To: Andriy Gapon <avg at icyb.net.ua>
Cc: bug-followup at freebsd.org
Subject: Re: kern/150517: [acpi] acpi_ec does not work properly on Lenovo S10[e] (due to dynamic switching to polled mode)
Date: Tue, 5 Oct 2010 19:54:14 +0200

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 On Tuesday 05 October 2010 11:09:02 Andriy Gapon wrote:
 > on 02/10/2010 09:31 David Naylor said the following:
 > > On Monday 27 September 2010 07:53:51 Andriy Gapon wrote:
 > >> Since you already looked at the linux code, could you please post a li=
 nk
 > >> to a place where the problematic condition is handled there?
 > >>=20
 > >> P.S. A service like http://lxr.linux.no/ or similar might be convenien=
 t.
 > >=20
 > > Sorry for the slow reply.  Your email was mistaken as spam.  I've told
 > > gmail to behave.
 > >=20
 > > It has been a long time since I looked at the code.  The function in
 > > question is http://lxr.linux.no/linux+v2.6.35.7/drivers/acpi/ec.c#L217
 > > with the actual check for controller reset at L238.
 > >=20
 > > Of note is the delay at L254.  It looks like it is almost the same thing
 > > my patch does, except it waits before whereas my patch waits after.
 >=20
 > David,
 >=20
 > can you dig up what kind of error messages you were getting from EC before
 > your patch?

 I ran a stress test of the EC by doing `while true; do acpiconf -i0; done` =
 and=20
 the error messages that produced are:

 acpi_ec0: wait timed out (no response), forcing polled mode
 acpi_ec0: EcRead: failed waiting to get data
 ACPI Exception: AE_NO_HARDWARE_RESPONSE, Returned by Handler for=20
 [EmbeddedControl] (20100915/evregion-588)
 ACPI Error: Method parse/execution failed [\\_SB_.BAT0._STA] (Node=20
 0xc4328520), AE_NO_HARDWARE_RESPONSE (20100915/psparse-633)
 ACPI Error: Method execution failed [\\_SB_.BAT0._STA] (Node 0xc4328520),=20
 AE_NO_HARDWARE_RESPONSE (20100915/uteval-185)
 acpi_ec0: EcRead: failed waiting to get data
 ACPI Exception: AE_NO_HARDWARE_RESPONSE, Returned by Handler for=20
 [EmbeddedControl] (20100915/evregion-588)
 ACPI Error: Method parse/execution failed [\\_SB_.BAT0._STA] (Node=20
 0xc4328520), AE_NO_HARDWARE_RESPONSE (20100915/psparse-633)
 ACPI Error: Method execution failed [\\_SB_.BAT0._STA] (Node 0xc4328520),=20
 AE_NO_HARDWARE_RESPONSE (20100915/uteval-185)
 acpi_ec0: EcRead: failed waiting to get data
 ACPI Exception: AE_NO_HARDWARE_RESPONSE, Returned by Handler for=20
 [EmbeddedControl] (20100915/evregion-588)
 ACPI Error: Method parse/execution failed [\\_SB_.BAT0.UPBS] (Node=20
 0xc43284a0), AE_NO_HARDWARE_RESPONSE (20100915/psparse-633)
 ACPI Error: Method parse/execution failed [\\_SB_.BAT0._BST] (Node=20
 0xc43284e0), AE_NO_HARDWARE_RESPONSE (20100915/psparse-633)
 acpi_ec0: EcRead: failed waiting to get data
 ACPI Exception: AE_NO_HARDWARE_RESPONSE, Returned by Handler for=20
 [EmbeddedControl] (20100915/evregion-588)
 ACPI Error: Method parse/execution failed [\\_SB_.BAT0._STA] (Node=20
 0xc4328520), AE_NO_HARDWARE_RESPONSE (20100915/psparse-633)
 ACPI Error: Method execution failed [\\_SB_.BAT0._STA] (Node 0xc4328520),=20
 AE_NO_HARDWARE_RESPONSE (20100915/uteval-185)
 acpi_ec0: EcRead: failed waiting to get data
 ACPI Exception: AE_NO_HARDWARE_RESPONSE, Returned by Handler for=20
 [EmbeddedControl] (20100915/evregion-588)
 ACPI Error: Method parse/execution failed [\\_SB_.BAT0._STA] (Node=20
 0xc4328520), AE_NO_HARDWARE_RESPONSE (20100915/psparse-633)
 ACPI Error: Method execution failed [\\_SB_.BAT0._STA] (Node 0xc4328520),=20
 AE_NO_HARDWARE_RESPONSE (20100915/uteval-185)
 acpi_ec0: EcRead: failed waiting to get data
 ACPI Exception: AE_NO_HARDWARE_RESPONSE, Returned by Handler for=20
 [EmbeddedControl] (20100915/evregion-588)
 ACPI Error: Method parse/execution failed [\\_SB_.BAT0._BST] (Node=20
 0xc43284e0), AE_NO_HARDWARE_RESPONSE (20100915/psparse-633)
 acpi_ec0: EcRead: failed waiting to get data
 ACPI Exception: AE_NO_HARDWARE_RESPONSE, Returned by Handler for=20
 [EmbeddedControl] (20100915/evregion-588)
 ACPI Error: Method parse/execution failed [\\_TZ_.TZ00._TMP] (Node=20
 0xc4328b80), AE_NO_HARDWARE_RESPONSE (20100915/psparse-633)

 The messages are not always consistent; sometimes they occur during boot. =
 =20
 Also sometimes the EC fails to powerdown the computer. =20

 > I also looked at your changes and at what Linux does and came up with some
 > changes to make our EC code more robust.  They are significantly based on
 > your patch, but also add some additional logic from Linux code.
 >=20
 > Can you try the patch?
 > http://people.freebsd.org/~avg/acpi_ec.patch
 > Thanks a lot!

 Two notes about your patch:
  - EcCheckStatus has changed position in the file resulting in a larger tha=
 n=20
 required change. =20
  - You no longer dynamically switch to polled mode.  Was that intentional?

 Your patchs works.  No errors were reported during the stress test, however=
 =20
 running acpiconf takes a noticeably longer time to complete (before and wit=
 h=20
 my patch it was instantaneous).  Setting debug.acpi.ec.timeout=3D25 improve=
 s=20
 responsiveness (reducing to 5 resulting in GPE query failed messages). =20

 Accoring to time acpiconf takes upto 3 seconds to complete, after setting=20
 debug.acpi.ec.timeout it takes upto 0.24 seconds. =20

 I changed EC_POLL_DELAY back to 5 and that didn't change anything. =20

 > P.S. I can describe why I didn't include some parts of your changes and
 > what new changes I made and "borrowed" from Linux, but later, if you'd
 > like.

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