Re: How to disable async resume for few selected devices (does it work?)

[Maxim Levitsky <maximlevitsky@gmail.com>]

On Wed, 2010-06-02 at 21:51 -0400, Alan Stern wrote: 
> On Thu, 3 Jun 2010, Maxim Levitsky wrote:
> 
> > I have a card reader on which one function implements SDHCI and other
> > MMC (to workaround windows bug....)
> > 
> > There is a way to disable MMC function, but is causes the device
> > sometimes to die on resume from disk/ram.
> > 
> > I today was told that MMC function is in fact _almost_ standard SDHCI
> > controller, and in fact now sdhci binds to it and works just fine.
> > 
> > However since both devices share same hardware they appear to have need
> > to be resumed one after another, and definitely not in parallel.
> > I tried to use device_disable_async_suspend on both pci devices and
> > indeed both power/async turns to false.
> > 
> > But they are still resumed in parallel:
> > (look how well mmc0 and mmc1 interleave...)
> > Why?
> 
> My guess is that you shouldn't have disabled async suspend on the PCI 
> devices but on their children instead.  That is, the PCI devices are 
> 0000:07:00.1 and 0000:07:00.2, but the devices causing your problem are 
> mmc0 and mmc1.  Or maybe you'd prefer to disable async suspend on all 
> four devices.
Nope, all childeren of both pci device has 'async' disabled.
Just checked that.

Best regards,
Maxim Levitsky

> 
> Alan Stern
>