Madhusudhan c wrote: > > Suppose a host controller is capable of suporting 8-bit and it tells > the core that it can support 8-bit. Now the card that is plugged in > might or might not support 8-bit based on the type of the card. There > is no field in the ext_csd which will tell you what bus width the card > can support.
My understanding is that 8-bit support on the card is not optional. ie: the card is not mmc 4 compliant if it doesn't support 8-bit and this is why there's no ext_csd field. The only case I could think of where bus testing would be needed would be if a controller was placed into a configuration where some pins were deliberately left unconnected (perhaps because space constraints prevented the extra 4 pins from being placed on a pcb) and there was no way to change the capabilities reported by the controller. But in any case - this is all hypothetical right now - one can't find a controller in the wild for love or money (well - Arasan will sell you a validation controller for $5000 but still...). As neither Pierre or myself is in a position to do any sort of tests on an 8-bit controller, we can't investigate or verify any of this. It certainly seems that you have access to an 8-bit controller. If you can help one or both of us get access to one, I'm sure we could work out the right thing to do. --phil - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
