Re: Problems with suspend/resume of pxa2xx_spi

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

Zik Saleeba wrote:
> I found that saving and restoring SSCR0, SSCR1, SSITR, SST0 (for
> pxa270) and SSPSP was enough to bring the system back to life again.
> 
> Would more experienced people like to comment on whether I'm on the
> right track here?

Is it possible that you did not check individually to see which of these
registers is the culprit?  SSITR is a test register that is surely
initialized to 0 on powerup, and it is never touched by the driver.  So
why would this have changed?  Likewise, SSPSP is not ever set by the
driver.  SSCR0, SSCR1, are both set at the end of pump_transfers, just
before the first transfer starts, if they differ from the values in
hardware, as they most likely will after suspend (and if they don't,
then it should not matter).

Is is possible that after resume, not all of these registers recover
their power-up state?  Is SSPSP really different after resume than
before?  SSPSP should not matter if the PSP mode is not selected in SSCR0.

Can you shed some light on these questions, while I continue to look?

-- 
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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