[U-Boot] [PATCH v2 1/4] tegra2: Seaboard's MMC has an 8-bit bus

[Stephen Warren]

Tom Warren wrote at Tuesday, October 04, 2011 2:52 PM:
> Stephen Warren wrote at Tuesday, October 04, 2011 10:33 AM:
> > Modify board_mmc_init to configure SDMMC4 for an 8-bit bus, since that's
> > what is wired up on the board.
> >
> [Tom Warren] Did you try this and then do a mmcinfo to see what you get back? On my Seaboard T20-A03,
> initializing with 8-bit arg gets you 1-bit back on mmcinfo; using 4-bit (as I had it) gets you back 4-
> bit. Although it's wired for all 8 data bits, I'm not sure the eMMC controller or device or I/F
> handles 8 bits correctly. Need to do some more research here, but we should leave this @ 4-bit for now
> IMO.

Ah yes, I see the same issue. I had only validated that running "mmc part"
and ext2load still operated correctly.

I see the exact same issue on Harmony's J26 port, which I'd also marked
as 8-bit.

I guess the Tegra MMC driver doesn't support 8-bit mode or something.
I'll take a quick look and see if there's anything obvious. If not,
I'll just drop that patch from the series.

Thanks for taking a look.

-- 
nvpublic