Messages in this thread | | | Date | Thu, 9 Apr 2009 14:17:41 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [linux-pm] [RFC][PATCH] Add late pm notifiers for hibernate |
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On Wed, 8 Apr 2009, Michael Holzheu wrote:
> From: Michael Holzheu <holzheu at linux.vnet.ibm.com> > > This patch is a suggestion to solve the issue reported by Ursula Braun: > https://lists.linux-foundation.org/pipermail/linux-pm/2009-March/020443.html > > On s390 we have device drivers that don't belong to a Linux bus. Therefore > we can't use the PM device callbacks (dev_pm_ops). The only way to get > informed that we hibernate or resume is the pm_notifier_call_chain.
I'm curious to know what device drivers these are that don't have a bus. Could they use the platform bus? That's more or less what it's intended for -- devices that don't fit anywhere else.
> Unfortunately some of our drivers need a frozen userspace to do their > hibernate actions and the current notifiers are called before userspace is > frozen. Another point is that we want our console driver to suspend as late > as possible so that we can see all the hibernate progress messages on the > console.
It's possible to avoid suspending the console at all if you boot with "no_console_suspend" as a kernel parameter.
Alan Stern
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