On Fri, May 7, 2010 at 1:45 AM, Jae hoon Chung <[email protected]> wrote: > Dear Andy > > Thanks for your comment.. > but i have some question... > > 2010/5/7 Andy Fleming <[email protected]>: >> On Wed, Apr 7, 2010 at 10:36 PM, Jae hoon Chung <[email protected]> wrote: >>> The patches do the following >>> 1. If mmc size is more than 2GB , we need to calculated using the >>> extended csd register. >> >> This description is slightly inaccurate. I have encountered MMC cards >> with 4GB capacity, which are not actually high-capacity cards. But >> certainly there's a bug in the current code where high-capacity MMC >> cards are not getting proper size calculations. >> > > that means 4GB capacity is not high-capacity cards, right? > i understood that higher than 2GB is supported high-capacity.. > if i mis-understood, i'll check the spec.
Well, the spec says anything over 2GB is high capacity, and should be accessed using block addressing. However, the 4GB card I used reported itself as not high-capacity, and was addressable via byte addressing. This works, because 4GB is addressable that way, but it's technically in violation of the spec. > >> >>> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c >>> index cf4ea16..c985924 100644 >>> --- a/drivers/mmc/mmc.c >>> +++ b/drivers/mmc/mmc.c >>> @@ -410,6 +410,10 @@ int mmc_change_freq(struct mmc *mmc) >>> if (ext_csd[212] || ext_csd[213] || ext_csd[214] || ext_csd[215]) >>> mmc->high_capacity = 1; >>> >>> + if (mmc->high_capacity) >>> + mmc->capacity = ((ext_csd[215] << 24) | (ext_csd[214] << >>> 16) | >>> + (ext_csd[213] << 8) | ext_csd[212]); >>> + >> >> >> This is off by a factor of block size. Capacity is supposed to be the >> size in bytes, and this sets it to the size in blocks, I believe. >> >> Hmm... I don't like that we are now doing the calculation twice for >> high-capacity MMC cards, but I guess that's fine for now, as this only >> affects v4 and higher, and extracting it is a bit more of a pain than >> I originally thought. >> >> On a side note, does this mean you have a high-capacity MMC card? And >> can you point me to a place to get one? We've been trying to test MMC >> high-capacity for a while, and have yet to find a real one (we found >> that 4GB one I mentioned, and it does normal byte-addressing). >> > > didn't you have high-capacity card? > we tested with 8GB moviNAND card, below is mmc card information using > that code.. Hmm...I'm not managing to find an actual card online for sale. Do you have a link? We had a high-capacity SD card, but no MMC card. > > Tran Speed: 52000000 > Rd Block Len: 512 > MMC version 4.3 > High Capacity: Yes > Capacity: 7840 MByte > Bus Width: 4-bit > > and if card is higher than 2GB, access mode selected sector mode.. > why does card do normal byte-addressing? Yours is clearly a proper high-capacity card. :) _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
