On Thu, 2009-10-29 at 11:27 +0100, Daniel Mack wrote: > On Wed, Oct 28, 2009 at 10:06:02AM -0700, Dan Williams wrote: > > On Wed, 2009-10-28 at 17:47 +0100, Daniel Mack wrote: > > > I did some more research on this and it turns out that the problem is > > > related to multi block transfers. At least, this is when it first > > > occurs. > > > > > > The libertas SDIO driver downloads two firmwares to the device, one > > > 'helper' and one 'real' firmware The first one only uses chunks of 64 > > > bytes each and that seems to work fine. The real firmware, however, > > > loads in 512 bytes chunks which the SDIO core breaks up into 16 blocks > > > of 32 bytes. And this is where the MXC host controller bails out with a > > > CRC error. Unfortunately, it does not give any more detailed information > > > about what exactly went wrong. > > > > > > The effect might be related to an errata entry[1], which is what I'm > > > currently investigating. To do so, I would like to limit the the > > > communication to singe-block transfers, just to exclude all other > > > possible (electrical, clock speed, ...) issues. I did that by setting > > > mmc->max_blk_count to 1 in the the host controller, but then again, > > > the libertas driver and/or the firmware doesn't like that and dies in > > > if_sdio_pro_real() with > > > > > > firmware wants 17 bytes > > > firmware helper signalled error > > A number of bytes requested has bit 1 set indicates an error, according > to the code if_sdio_prog_real(). Is there any more information in such > cases? An error code that tells us about the real reason maybe? Not that I know of; the helper is pretty simple. The v9 SD8686 vendor driver assumes that any helper error is a CRC error, and retries that block a few times before failing. But the helper asking for 17 bytes seems a bit suspicious. Are you sure there aren't any TX/RX issues with your SDHC and the connections to the card? > > All the Marvell documentation (v5 at least) refers to 512-byte transfers > > of the second-stage firmware in 32-byte blocks: > > > > Section 2.2.1.1 of the v5 spec states: > > What documentation is that? Is it publically available? http://wiki.laptop.org/images/f/f3/Firmware-Spec-v5.1-MV-S103752-00.pdf Dan -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
