Re: MMC: Make the configuration memory resource optional

Guennadi Liakhovetski
2009-07-31T06:55:30Z

On Thu, 30 Jul 2009, Ian Molton wrote:

> Guennadi Liakhovetski wrote:
>
> > While you're at it, please, consider swapping the two lines in
> > tmio_mmc_probe():
> >
> > - tmio_mmc_clk_stop(host);
> > reset(host);
> > + tmio_mmc_clk_stop(host);
> >
> > Otherwise, I think, reset causes problems trying to access the controller
> > with disabled clock. At least this is needed on SuperH.
>
> Interesting. I'll see what the result of this is on TMIO - This sequence was
> garnered from the WinCE driver for the chip.
>
> I cant see _why_ this should be a problem, as this disables the card clock,
> not HCLK. Could you debug further in tmio_mmc_clk_stop() please and see if
> reordering only one of the two IO accesses cures this?

Not sure I understood the "reordering only one of the two IO accesses"
correctly, but I swapped the two sd_ctrl_write16() calls in
tmio_mmc_clk_stop() and no, it didn't cure the problem.

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer