On Fri, May 1, 2015 at 7:39 AM, Xuebing Wang <xbing6@xxxxxxxxx> wrote: > I got my eMMC working on kernel v4.0.1 by: > 1) In device tree, use 8 data lines (rather than 4 lines for sdhc) Ok, great. This makes sense. > 2) Force ext_csd.rev to be 4 > ------------------------- > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c > index 1d41e85..aa1ca6c 100644 > --- a/drivers/mmc/core/mmc.c > +++ b/drivers/mmc/core/mmc.c > @@ -355,6 +355,7 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 > *ext_csd) > * are authorized, see JEDEC JESD84-B50 section B.8. > */ > card->ext_csd.rev = ext_csd[EXT_CSD_REV]; > + card->ext_csd.rev = 4; > > card->ext_csd.raw_sectors[0] = ext_csd[EXT_CSD_SEC_CNT + 0]; > card->ext_csd.raw_sectors[1] = ext_csd[EXT_CSD_SEC_CNT + 1]; > ------------------------- > > eMMC on my board is Micron "MTFC4GLDDQ-4M IT", according to its datasheet, > it is "JEDEC/MMC standard version 4.41-compliant > (JEDEC Standard No. 84-A441)", and its "Extended CSD revision" (EXT_CSD_REV) > = 5 > > This seems either because kernel does not handle (ext_csd == 5) correctly, > or there is an firmware issue in Micron "MTFC4GLDDQ-4M IT" (in terms of > JEDEC standard compliance), what do you think? I will let the mmc experts comment on this one. Regards, Fabio Estevam -- 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
