Re: power management routines for NAND driver

[Todd Poynor <tpoynor@mvista.com>]

Vitaly Wool wrote:

> I've looked through mtd code and found mtd_pm_callback that should be 
> called to handle PM events. This callback should in turn call 
> mtd->suspend/mtd->resume functions, if any. Therefore one evident way of 
> PM stuff implementation for this NAND flash is to provide suspend/resume 
> functions. However, pm_send (that calls mtd_pm_callback) is never called
> on ARM targets. So I doubt if it's appropriate to implement PM for the 
> driver this way since it's looking somehow obsolete.
> 
> Another way could be define the platform_device and provide its 
> suspend/resume functions, that would be called during the power state 
> transition. 

Yes, the pm_send etc. APM-style calls are deprecated.  The Linux Driver 
Model PM hooks (incl. struct device_driver suspend/resume callbacks) are 
the way to do it now.  I floated a patch for another board in thread 
"MTD PM Resume" in July that does approximately what you're talking 
about, although calling existing Intel/Sharp CFI NOR flash routines.  If 
there's no objections to that style of PM support then I'll check it in.

-- 
Todd