Re: [PATCH] pxa2xx_spi: wait_rx_stall before deasserting CS on PIO mode

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

Ned Forrester wrote:
> Daniel Ribeiro wrote:
> In a past message, you showed the automatic declarations that went with
> the above code:
> 
> >	struct spi_transfer t;
> >	struct spi_message m;
> 
> While spi_message_init() zeros the memory in "m", you don't show any
> code above, other than your assignments, that clears the memory in "t".
> Thus, if you omit the assignments for t.delay_usecs or t.speed_hz (or
> any other member of t), then you are passing uninitialized memory.  You
> could use memset to clear t, or dynamically allocate zeroed memory.
> 
> Normally, you use the per-transfer values:
> 
> 	t.bits_per_word
> 	t.speed_hz
> 
> only when you need to make them different from the default values set
> when you previously called spi_setup()

I forgot to mention that if either of these values is zero, then the
default parameters set by initialization or spi_setup are used.  If
either value is non-zero, then the defaults are overridden.  In your
case, the uninitialized memory overrode the defaults.

-- 
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


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