LKML Archive on
help / color / mirror / Atom feed
From: Pavel Machek <>
To: "Rafael J. Wysocki" <>
Cc: "Len Brown" <>,
	"ACPI Devel Maling List" <>,
	"Andrew Morton" <>,
	"Carlos Corbacho" <>,
	"Linus Torvalds" <>,
	LKML <>,
	"pm list" <>,
	"Shaohua Li" <>,
	"Felix Möller" <>,
	"Arthur Erhardt" <>,
	"Matthew Garrett" <>
Subject: Re: [PATCH] ACPI PM: Restore the 2.6.24 suspend ordering
Date: Sun, 30 Mar 2008 13:18:44 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>


> Please consider pushing the appended patch for 2.6.25.
> It fixed the regression described at:
> details in the changelog.

> ---
> From: Rafael J. Wysocki <>
> Some time ago it turned out that our suspend code ordering broke
> some NVidia-based systems that hung if _PTS was executed with one of
> the PCI devices, specifically a USB controller, in a low power state.
> Then, it was noticed that the suspend code ordering was not compliant
> with ACPI 1.0, although it was compliant with ACPI 2.0 (and later),
> and it was argued that the code had to be changed for that reason
> (ref.  So we did,
> but evidently we did wrong, because it's now turning out that some
> systems have been broken by this change (refs.
> ,
>  [I said
> at that time that something like this might happend, but the majority
> of people involved thought that it was improbable due to the
> necessity to preserve the compliance of hardware with ACPI 1.0.]
> This actually is a quite serious regression from 2.6.24.
> Moreover, the ACPI 1.0 ordering of suspend code introduced another
> issue that I have only noticed recently.  Namely, if the suspend of
> one of devices fails, the already suspended devices will be resumed
> without executing _WAK before, which leads to problems on some
> systems (for example, in such situations thermal management is
> broken on my HP nx6325).  Consequently, it also breaks suspend
> debugging on the affected systems.
> Note also, that the requirement to execute _PTS before suspending
> devices does not really make sense, because the device in question
> may be put into a low power state at run time for a reason unrelated
> to a system-wide suspend.
> For the reasons outlined above, the change of the suspend ordering
> should be reverted, which is done by the patch below.

But this will break those few nvidia-based systems, no?

this may have been a good idea in -rc1 days, but we are in -rc7
now... and the patch is slightly big.

What about something like: (hand-edited patch, sorry)

 Index: linux-2.6/drivers/acpi/sleep/main.c
 --- linux-2.6.orig/drivers/acpi/sleep/main.c
 +++ linux-2.6/drivers/acpi/sleep/main.c
 @@ -26,21 +26,6 @@ u8 sleep_states[ACPI_S_STATE_COUNT];
  static u32 acpi_target_sleep_state = ACPI_STATE_S0;
 static bool acpi_sleep_finish_wake_up;
- /*
-  * ACPI 2.0 and later want us to execute _PTS after suspending devices, so we
-  * allow the user to request that behavior by using the 'acpi_new_pts_ordering'
-  * kernel command line option that causes the following variable to be set.
-  */
 static bool new_pts_ordering = true;
 -static int __init acpi_new_pts_ordering(char *str)
 +static int __init acpi_old_pts_ordering(char *str)
 	new_pts_ordering = false;
 	return 1;
 -__setup("acpi_old_pts_ordering", acpi_old_pts_ordering);
 +__setup("acpi_new_pts_ordering", acpi_new_pts_ordering);
  static int acpi_sleep_prepare(u32 acpi_state)
 Index: linux-2.6/Documentation/kernel-parameters.txt
 --- linux-2.6.orig/Documentation/kernel-parameters.txt
 +++ linux-2.6/Documentation/kernel-parameters.txt
 @@ -170,11 +170,6 @@ and is between 256 and 4096 characters. 
  	acpi_irq_isa=	[HW,ACPI] If irq_balance, mark listed IRQs used by ISA
  			Format: <irq>,<irq>...
 -	acpi_new_pts_ordering [HW,ACPI]
 +	acpi_old_pts_ordering [HW,ACPI]
 -			Enforce the ACPI 2.0 ordering of the _PTS control
 +			Enforce the ACPI 1.0 ordering of the _PTS control
 			method wrt putting devices into low power states
 -			default: pre ACPI 2.0 ordering of _PTS
 +			default: ACPI 2.0 ordering of _PTS
  	acpi_no_auto_ssdt	[HW,ACPI] Disable automatic loading of SSDT
  	acpi_os_name=	[HW,ACPI] Tell ACPI BIOS the name of the OS

(cesky, pictures)

  reply	other threads:[~2008-03-30 11:18 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-30  1:19 Rafael J. Wysocki
2008-03-30 11:18 ` Pavel Machek [this message]
2008-03-30 11:58   ` Rafael J. Wysocki
2008-03-30 12:28     ` Pavel Machek
2008-03-30 13:15       ` Rafael J. Wysocki
2008-04-01  8:45         ` Pavel Machek
2008-04-01 14:38           ` Felix Möller
2008-04-01 19:55           ` Rafael J. Wysocki
2008-04-02 13:00             ` Pavel Machek

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
    --subject='Re: [PATCH] ACPI PM: Restore the 2.6.24 suspend ordering' \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).