topic Re: iMX28 eMMC v5.0 support in i.MX Processors

iMX28 eMMC v5.0 support

spicard — Tue, 17 Feb 2015 17:56:18 GMT

Hello,

the datasheet of the iMX28 say that eMMC v4.3 and eMMC v4.4 is supported.

Can I use eMMC v5.0 without problems?

Will it be possible to use the new features of v5.0?

I'm using linux kernel 3.10.

Thank you

Re: iMX28 eMMC v5.0 support

gusarambula — Tue, 17 Feb 2015 21:47:48 GMT

Unfortunately only eMMC v4.3 and eMMC v4.4 are supported by the SSP Module of the i.MX28.

Other community users have successfully used eMMC v5.0 on the i.MX53 and i.MX6 by changing some settings and making the eMMC v5.0 work as eMMC v4.4 like on the following threads.

https://community.freescale.com/thread/325001

https://community.freescale.com/thread/304771

In any case all new features of eMMC v5.0 like HS400 mode and Data Strobe won’t be available

Re: Re: iMX28 eMMC v5.0 support

spicard — Wed, 18 Feb 2015 13:54:15 GMT

I did the following modification in the kernel 3.10 (drivers\mmc\core\mmc.c) to skip the error message and the eMMC v5.0 seems to work fine.

	if (card->ext_csd.rev > 7) {
	pr_err("%s: unrecognised EXT_CSD revision %d\n",
	mmc_hostname(card->host), card->ext_csd.rev);
	err = -EINVAL;
	goto out;
	}

I also tried the kernel 3.18 without any modifications and it also seems to work fine.

If I don't need the new features introduced since v4.41, is it safe to use a v5.0 eMMC with the i.MX28?

Re: iMX28 eMMC v5.0 support

gusarambula — Wed, 18 Feb 2015 20:10:16 GMT

It is not officially supported by the i.MX28 controller but eMMC5.0 is backwards compatible with eMMCv4.4 so as long as it's being used as eMMCv4.4 (not using any v5.0 features) you should be fine.