[PATCH v1 3/5] spi: Added way to check for pm support for flash devices

Kamal Dasu kdasu.kdev at gmail.com
Mon Feb 6 11:32:54 PST 2017


Patches 3-5 are not needed. I will refactor patch 1-2 and send a v2 version.

Thanks
Kamal

On Mon, Feb 6, 2017 at 11:46 AM, Mark Brown <broonie at kernel.org> wrote:
> On Mon, Feb 06, 2017 at 11:44:09AM +0100, Cyrille Pitchen wrote:
>> Le 04/02/2017 à 21:47, Kamal Dasu a écrit :
>
>> >> What is "flash pm" and how would a client use it given that no API for
>> >> actually managing power is being added here?  Someone looking at the API
>> >> needs to be able to figure these things out and right now I can't see
>> >> how they'd do that...o
>
>> > The flash_pm function just indicates if  m25p80 resume op that does a
>> > spi_nor_pm_rescan() is needed, and by default will do nothing for
>> > other platforms. So the basic idea of the patches was to execute the
>> > only necessary spi_nor_pm_rescan() on resume when flash parts are
>> > reset on suspend. So from controller perspective there is no
>
> I can't tell what this means, sorry, and writing this e-mail does not
> address the incomprehensibility of the API.  Why would the controller
> driver have anything to do with whatever this spi_nor_pm_rescan()
> operation does?
>
>> I don't understand why we extend in the SPI framework API to add power
>> management features but only for SPI flashes. I guess concerning the power
>> management, there is nothing special about SPI flashes: they are just SPI
>> devices like others. So why not extend the SPI framework, if needed, with
>> something working for all SPI devices, not just for SPI flashes.
>
> It's already possible for SPI devices to do runtime PM.



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