[PATCH 2/2 V3] MXS: Implement DMA support into mxs-i2c

Marek Vasut marex at denx.de
Mon Jul 16 09:06:07 EDT 2012


Dear Wolfram Sang,

> Marek,
> 
> > > I am also still interested to check the runtime switching, but it might
> > > take another month until I can really hack on it.
> > 
> > Good, there is some bit that probably needs to be flipped to allow this
> > switching. I managed to get this working with SPI, not with i2c though.
> > With
> 
> Ah, hearing that it works with SPI is good news.
> 
> > i2c, if I restarted the controller inbetween each transaction, it worked
> > ... which is not what I'd like to see there.
> 
> Agreed.
> 
> > > > No, it doesn't. See above about small transfers. Consider the easy
> > > > situation where you have sensor on one bus (so you do PIO because you
> > > > transfer small data) and you have EEPROM on other bus, where you use
> > > > DMA because you transfer large data. And the mixed mode isn't there
> > > > yet.
> > > 
> > > I fully understand what you want to configure. I did before. Yet,
> > > devicetree bindings are not platform_data and shouldn't be used like
> > > them.
> > 
> > But then, how would you configure this detail on a per-bus basis? Well
> > all
> 
> This is a question for devicetree-discuss.

Did you Cc it?

> > patch actually fixes a real issue, I'd like to have it in ASAP and it's
> > been aboue three months already, which sucks.
> 
> I am open to ideas improving the situation (which is: a lot more
> patches, but not a lot more reviewers)
> 
> Thanks,
> 
>    Wolfram

Best regards,
Marek Vasut



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