[PATCH] net: davinci_emac: Add pre_open, post_stop platform callbacks

Ben Hutchings bhutchings at solarflare.com
Thu May 3 16:22:22 EDT 2012


On Thu, 2012-05-03 at 19:25 +0000, Bedia, Vaibhav wrote:
> On Fri, May 04, 2012 at 00:16:32, Mark A. Greer wrote:
> [...]
> > > 
> > > So, if I understood this correctly, it's effectively like blocking a low power
> > > state transition (here wfi execution) when EMAC is active?
> > 
> > Assuming "it" is my patch, correct.
> > 
> 
> Recently I was thinking about how to get certain drivers to disallow some or all
> low power states and to me this also seems to fall in a similar category.
> 
> One of the suggestions that I got was to check if the 'wakeup' entry associated with
> the device under sysfs could be leveraged for this. The PM code could maintain
> a whitelist (or blacklist) of devices and it decides the low power state to enter
> based on the 'wakeup' entries associated with these devices. In this particular case,
> maybe the driver could simply set this entry to non-wakeup capable when necessary and
> then let the PM code take care of skipping the wfi execution.
> 
> Thoughts/brickbats welcome :)

You can maybe (ab)use the pm_qos mechanism for this.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.




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