Hi Pierre, IMHO the issue is there is no upper bound limit to the valid address range in sdio_io_rw_ext_helper() in sdio_io.c.
I call sdio_memcpy_toio() as it enables the incrementing address flag in the CMD53 command but if I try passing too much data then the actual address of the subsequent CMD53 commands are erroneously incremented out of range. The difficulty is the SDIO card can transfer 8 blocks in a single CMD53 command using the incrementing address flag. However sdio_io_rw_ext_helper() will not prevent the attempt at sending 9 blocks transferred as 2 CMD53 commands of 8 blocks + 1 block and the last block goes to the wrong address. This causes a big system crash. I suspect the SDIO card internally resets and the MMC sub-system can't handle the error condition. This means the card driver needs to know that it cannot use sdio_memcpy_toio() to send any size of data but must ensure it does not exceed 8 blocks before calling sdio_memcpy_toio(). IMHO this makes the card driver undesirably tightly coupled with the core driver. OK. I'll workaround it using multiple calls to sdio_memcpy_toio(). BTW. Is the API for the exported SDIO core functions documented anywhere ? Thanks, Regards, Dean. On Tue, 2007-11-20 at 11:58 +0100, Pierre Ossman wrote: > On Mon, 19 Nov 2007 11:44:54 +0000 > Dean Jenkins <[EMAIL PROTECTED]> wrote: > > > This E-mail is for the attention of Pierre Ossman (MMC sub-system > > maintainer) > > A cc helps if you want my attention. ;) > > > > > Hi Pierre, > > > > I've being trying to get SDIO block-mode with incrementing address to > > work on an OMAP2430 based reference board with an SDIO card. > > > > Looking at the latest code ( as of 19/11/2007 ) on the mmc-git tree (I'm > > not a git expert so I'm not sure how to reference the codebase). I have > > a comment to make concerning the following code snippet... > > git log or git show will give you your current top commit id. > > > > I think the lines > > > > 227 if (incr_addr) > > 228 addr += size; > > > > are incorrect and should be removed. I think the SDIO increment address > > parameter relates to the internal operation of the SDIO card and NOT to > > the external register address of the FIFO. In other words, I think with > > incrementing address enabled in block mode, the register address of the > > FIFO in the SDIO function register space will be erroneously changed on > > the next block write and will fail (it seems to fail on my card). It > > seems strange to change the register address ? > > > > I don't follow. The SDIO specification very clearly defines the behaviour of > incrementing address. The referenced code is very much needed to keep that > behaviour when we need to split up the transfer. > > I assume what you want is multiple transactions with incrementing address, > but each transaction restarting at the same base address. In that case you'll > have to call the sdio register functions multiple times. > > Rgds -- Dean Jenkins Embedded Software Engineer MontaVista Software (UK) Professional Services Division - 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/
