Re: [RFC 0/6] mmc: sdhi: add basic r8a7795 support

[Wolfram Sang <wsa@the-dreams.de>]

[-- Attachment #1: Type: text/plain, Size: 1636 bytes --]

Hi Dirk,

> First, regarding the clocks, if anybody from the experts could advise me how
> we'd like to interface dynamic clocks to the existing Gen3 clock code, that
> would be really welcome:

I am not the clock expert, but I try to have a look next week.

> Second, I'm mainly interested in eMMC support for the Salvator-X. Therefore

OK, nice to know. I have eMMC running now, without DMA and HS200, of
course. My patches need some refactoring, though.

> I picked (hopefully) all patches from the Renesas BSP to
> renesas-drivers-2016-01-13-v4.4

Yes, that's where I picked your clock patches from :)

> so I'd suspect some memory overwriting. But what confuses me is that the
> same code works fine on the the 4.2 based Renesas BSP. I have no idea
> regarding this, yet.

I usually don't have high hopes that putting more than a trivial amount
of any BSP code on top of upstream will result in success ;)

My obviuos plan is to work incrementally. First basic support, then DMA,
then UHS-I/HS200. Review, refactor existing patches. Upstream first, etc
pp... You know all this, I guess.

> And third, from reading the r8a7795 manual I think the manual talks about
> 
> https://github.com/dirkbehme/linux-renesas-rcar-gen3/commit/f2a727c859916d59dca85dbb72c1b61da3fd6da0
> 
> But testing this it doesn't work. So either the manual is wrong, or I missed
> anything else.

I have seen this patch and my gut feeling is that it won't make a
difference? SCLKDIVEN is like CBUSY plus some more cycles AFAIU. But I
am not working on DMA issues now, this has to wait.

Kind regards,

   Wolfram


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]