Re: Problems with suspend/resume of pxa2xx_spi

[Ned Forrester <nforrester-/d+BM93fTQY@public.gmane.org>]

Zik Saleeba wrote:
> Here's the contents of the registers before suspend:
> 
> SSCR0=00000387

This means: 1/4 clock rate, SSP *enabled*, and 8 bit data.
You don't want to restore the SSP to the running state after resume
because it should not have been running after suspend.  I will comment
more in the next email.

> SSCR1=00000ec0
> SSSR=0000f024
> SSITR=00000000
> SSTO=00000000
> SSPSP=00000000
> 
> And after suspend:
> 
> SSCR0=00000000
> SSCR1=00000000
> SSSR=0000f004
> SSITR=00000000
> SSTO=00000000
> SSPSP=00000000
> 
> I chose to reinitialise the registers to a known correct state rather
> than leave them in their post-suspend state. You may have some better
> ideas about what to do with them.

This state is not the "correct" state to restore.  It has been captured
before the driver is shutdown in preparation for suspend.  If any
restoration is required, it would be to the shutdown state.

-- 
Ned Forrester                                       nforrester-/d+BM93fTQY@public.gmane.org
Oceanographic Systems Lab                                  508-289-2226
Applied Ocean Physics and Engineering Dept.
Woods Hole Oceanographic Institution          Woods Hole, MA 02543, USA
http://www.whoi.edu/sbl/liteSite.do?litesiteid=7212
http://www.whoi.edu/hpb/Site.do?id=1532
http://www.whoi.edu/page.do?pid=10079


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