On Thu, 8 Oct 2009 20:38:26 +0200 Pierre Ossman <pierre@xxxxxxxxx> wrote: > > > > In practice, I expect that the timings are close enough that this > > will work anyway, but I think the situation is analogous to HS-MMC > > vs HS-SD. There the timings are slightly different and you felt it > > was enough to justify a separate host cap for each one. > > > > It's difficult to say without seeing the spec. But if things are not > backwards compatible, then we should probably add either a new timing > mode, or a new bus mode (where we have open drain and push pull > today). > > > In fact, thinking about it in those terms, it suggests we need to > > retroactively introduce a reduced-voltage MMC host flag too, just in > > case SDHCI 3.0 controllers barf on those cards... > > > > Maybe. Again, it's difficult to say without seeing the specifics of > the new specification. Make sense. So, I guess the question is do we assume the best case (in which case there is no additional work to do - the code that is now in allows low voltage SDIO cards to try and run) or the worst case and add pre-emptive mode flags? David, you've actually seen the new spec right? What's your opinion? --phil
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