lkml.org 
[lkml]   [2007]   [Dec]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: PNP: do not stop/start devices in suspend/resume path
On Thu, 6 Dec 2007 16:25:57 -0700
Bjorn Helgaas <bjorn.helgaas@hp.com> wrote:

> PNP: do not stop/start devices in suspend/resume path
>
> Do not disable PNP devices in the suspend path. We still call
> the driver's suspend method, which should prevent further use of
> the device, and the protocol suspend method, which may put the
> device in a low-power state.
>
> I'm told that Windows puts devices in a low-power state (Linux
> does this in the protocol suspend method), but does not use _DIS
> in the suspend path. Other relevant references:
>
> - In the ACPI 3.0b spec, I can't find any mention of _DIS in
> connection with sleep. And Device Object Notifications,
> Section 5.6.3, Table 5-43, says we should get a bus check
> after awakening if hardware was removed while we slept.
>
> - This: http://msdn2.microsoft.com/en-us/library/ms810079.aspx
> makes a similar point about how the OS re-enumerates devices
> as a result of a power state change (3rd last paragraph of
> text).
>
> - This: http://msdn2.microsoft.com/en-us/library/aa489874.aspx
> suggests that Windows only stops a device to rebalance hardware
> resources.
>
> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
>

Tested-by: Pierre Ossman <drzeus@drzeus.cx>

No noticeable issues with suspend or hibernate using this patch.

Rgds
Pierre
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2007-12-13 09:29    [W:0.192 / U:0.168 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site