JEDEC V5 eMMC on Kernel 3.10 - i.mx6D

[phillogden]

Hi Guys,

I've been working on a product using the iMX6D chipset and linux kernel version 3.10. We just went into pre-production and had to substitute the eMMC part for a different one. Unfortunately we selected a part with a newer JEDEC standard than 3.10 can support (V5).

I was wondering if you had a method to get JEDEC V5 running on kernel 3.10? I am very hesitant to move to a newer kernel this late in the product development, so I attempted to port the mmc drivers from kernel 3.19 to 3.10. This unfortunately snowballed into changing almost every diver in the source tree (DMA for starters, and from there, everything else really).

I was wondering if anyone had some experience with 3.10 Kernel and newer JEDEC MMC standards? Apart from changing kernel versions or changing the chip again.

[igorpadykov]

also one can look at

i.mx6 with eMMC 5.0 SDR or DDR interface? | NXP Community

~igor

[lategoodbye · Accepted solution]

Hi Phill,

we had a similiar issue with i.MX28. The mmc core refused the MMC because of it's unknown EXT_CSD_REV. So maybe backporting relevant MMC core changes could be the solution (no need to touch any driver).

Here is a starting point for the changes:

https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/drivers/mmc/core/mmc.c?id=03...

Stefan

[phillogden]

Thanks! That's done the trick!

Did you also have to recompile the mfgtool kernel? I've managed to build the kernel and boot into the rootfs for mfgtool, but the usb isn't being enumerated up and being detected by the host machine. It just seems to sit on "UTP: Waiting for device to appear"

I'll probably make a new forum post for this as well. :smileyhappy:

[lategoodbye]

Yes, you will need to patch the mfgtool kernel, too.