Re: [linux-pm] question on resume()

2007-01-31 Thread Rafael J. Wysocki
On Wednesday, 31 January 2007 16:48, Alan Stern wrote: > On Wed, 31 Jan 2007, Rafael J. Wysocki wrote: > > > On Tuesday, 30 January 2007 23:32, Rafael J. Wysocki wrote: > > > [Added linux-pm to the Cc list, because I'm going to talk about things > > > that > > > I know only from reading the code.

RE: [linux-pm] question on resume()

2007-01-31 Thread Woodruff, Richard
> Again you misunderstood the question. The driver must start queued I/O > when its resume() method is called. It should then be okay for the driver > to call wake_up_interruptible(), even before tasks are unfrozen. I kind of like the way MontaVista worked around this in some 2.4 drivers where

Re: [linux-pm] question on resume()

2007-01-31 Thread Alan Stern
On Wed, 31 Jan 2007, Oliver Neukum wrote: > Am Mittwoch, 31. Januar 2007 16:54 schrieb Alan Stern: > > On Wed, 31 Jan 2007, Pavel Machek wrote: > > > > "cease IO"? No, I believe it is enough not to start new I/O. Userspace > > > is frozen at that point, it can't ask you to do I/O. > > > > There

Re: [linux-pm] question on resume()

2007-01-31 Thread Oliver Neukum
Am Mittwoch, 31. Januar 2007 16:54 schrieb Alan Stern: > On Wed, 31 Jan 2007, Pavel Machek wrote: > > "cease IO"? No, I believe it is enough not to start new I/O. Userspace > > is frozen at that point, it can't ask you to do I/O. > > There may be I/O requests sitting in a queue, already submitted

Re: [linux-pm] question on resume()

2007-01-31 Thread Alan Stern
On Wed, 31 Jan 2007, Pavel Machek wrote: > Hi! > > > > Yes, it will. The process freezer can only return success if there are > > > no more > > > TASK_UNINTERRUPTIBLE tasks. Otherwise it fails (after a timeout). > > > > So, this means, on suspend(): > > > > 1. Don't worry about TASK_UNINTERR

Re: [linux-pm] question on resume()

2007-01-31 Thread Alan Stern
On Wed, 31 Jan 2007, Rafael J. Wysocki wrote: > On Tuesday, 30 January 2007 23:32, Rafael J. Wysocki wrote: > > [Added linux-pm to the Cc list, because I'm going to talk about things that > > I know only from reading the code.] > > > > On Tuesday, 30 January 2007 17:50, Oliver Neukum wrote: > > >

Re: [linux-pm] question on resume()

2007-01-31 Thread Pavel Machek
Hi! > > > So, this means, on suspend(): > > > > > > 1. Don't worry about TASK_UNINTERRUPTIBLE > > > 2. Do worry about TASK_INTERRUPTIBLE > > > We have to cease IO and must not call wake_up_interruptible() > > > > "cease IO"? No, I believe it is enough not to start new I/O. Userspace > > is froze

Re: [linux-pm] question on resume()

2007-01-31 Thread Oliver Neukum
Am Mittwoch, 31. Januar 2007 10:36 schrieb Pavel Machek: > Hi! > > > > Yes, it will. The process freezer can only return success if there are > > > no more > > > TASK_UNINTERRUPTIBLE tasks. Otherwise it fails (after a timeout). > > > > So, this means, on suspend(): > > > > 1. Don't worry abou

Re: [linux-pm] question on resume()

2007-01-31 Thread Pavel Machek
Hi! > > Yes, it will. The process freezer can only return success if there are no > > more > > TASK_UNINTERRUPTIBLE tasks. Otherwise it fails (after a timeout). > > So, this means, on suspend(): > > 1. Don't worry about TASK_UNINTERRUPTIBLE > 2. Do worry about TASK_INTERRUPTIBLE > We have to