From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: [RFC][PATCH 0/2] Export platform_pci_set_power_state() and make radeonfb use it
Date: Tue, 24 Mar 2009 23:00:46 +0100
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Cc: Jesse Barnes <jbarnes@virtuousgeek.org>,
       Linux PCI <linux-pci@vger.kernel.org>,
       pm list <linux-pm@lists.linux-foundation.org>,
       LKML <linux-kernel@vger.kernel.org>,
       Linus Torvalds <torvalds@linux-foundation.org>,
       Andrew Morton <akpm@linux-foundation.org>,
       Alex Deucher <alexdeucher@gmail.com>
References: <200903210003.55161.rjw@sisk.pl> <200903241200.37982.rjw@sisk.pl> <1237929175.25062.727.camel@pasglop>
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On Tuesday 24 March 2009, Benjamin Herrenschmidt wrote:
> On Tue, 2009-03-24 at 12:00 +0100, Rafael J. Wysocki wrote:
> 
> > In fact I have yet another idea.  If we use the "retransmission with exponential
> > backoff" algorithm in pci_raw_set_power_state(), we won't have to add any
> > extra parameters to pci_set_power_state() and the radeon case will be covered
> > automatically.  That should also cover any other devices having similar
> > problems IMO.
> > 
> > A patch to implement that is appended, please tell me what you think.
> 
> This is crazy....
> 
> Most devices don't need that and those who are a bit "touchy" may well
> puke on being written to too fast while they are in the middle of
> the transition.
> 
> Let's wait to see if Alex from ATI has an answer here, and if not, I
> would suggest keeping the dirt inside radeonfb.

OK, so what would you like to do exactly?

The only thing I see is not to set current_state to PCI_D2 before calling the
final pci_set_power_state().

Rafael
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