As part of few other fixes and enhancements to u-boot MMC code, I sent a similar but slightly different patch yesterday. I have an eMMC High-Capacity card (4GB) and it works fine with this patch. But I do believe there are 4GB MMC cards that don't advertise them as High-Capacity cards and work with the byte addressing. By the way, how do I make sure that the fixes and enhancements that I submit are in line with what is expected and becomes part of the mainline code.
- Alagu Sankar Minkyu Kang wrote: > Dear Andy, > > On 7 May 2010 16:52, Andy Fleming <[email protected]> wrote: > >> 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. :) >> > > So, what is the conclusion or this patch? > Modify the patch? or NAK this patch? > Please let him know. > > Thanks > Minkyu Kang > _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
