Re: [PATCH 5/8] dmaengine: ste_dma40: Ensure src and dst registers are configured correctly

From: Arnd Bergmann
Date: Tue Apr 09 2013 - 16:38:38 EST


On Tuesday 09 April 2013, Lee Jones wrote:
> On Tue, 09 Apr 2013, Arnd Bergmann wrote:
>
> > On Tuesday 09 April 2013, Lee Jones wrote:
> > > Confusingly d40_log_cfg() is used to set up the logical channel
> > > configuration registers, but d40_phy_cfg() is used to configure
> > > physical and logical registers, so it should be called in both
> > > cases. It is the function call's final attribute which determines
> > > whether it's a physical or logical channel, not whether the
> > > function is called or not.
> >
> > So how did it ever work? Your description sounds like it was
> > broken all along, but I would assume that someone tested the code.
>
> From what I can see, not.
>
> My best guess is that the 'test' was to see if the configuration
> changed using the debug print at the end of the function. I don't see
> how else the configuration can be written to hardware.

Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
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